AMENDED OPINION
CUDAHY, Circuit Judge.Plaintiffs brought this suit, individually and on behalf of all exercise persons, grooms and hot walkers (collectively, “backstretehers”) at Illinois race tracks, seeking declaratory and injunctive relief from certain investigative practices authorized by the Illinois Racing Board (the “Board”) and carried out by the Illinois Department of Law Enforcement (“IDLE”) on the ground that these practices violated the Fourth Amendment, as applied to the state of Illinois through the Fourteenth Amendment. The challenged practices included warrantless searches of the back-stretchers’ on-track dormitory rooms and investigatory stops and searches of the backstretehers’ persons within the race track enclosure. Plaintiffs also challenged the Board’s policy of granting them occupation licenses only upon their consent to these searches. The defendants argued that the plaintiffs lack a legitimate expectation of privacy owing to pervasive state regulation of the horse-racing industry, to the nature of the premises searched and to the plaintiffs’ implied consent to the searches when they accepted their employment. The district court granted the plaintiffs’ motion for a preliminary injunction and, later, enjoined the searches permanently on plaintiffs’ motion for summary judgment. We affirm.
Backstretehers work at race tracks, feeding, grooming, exercising and generally taking care of the race horses. They are employed by the horses’ trainers and licensed by the Board under authority vested in the Board by the Horse Racing Act of 1975 (the “Act”), Ill.Ann.Stat. ch. 8, para. 37 (Smith-Hurd Supp.1987). Many of the backstretehers live in dormitory rooms located in the backstretch, which is the area where the horses are stabled. These rooms are owned by the race track and made available to the trainers and the backstretehers in their employ at no charge. Backstretehers do not have to live at the track, but many do so for reasons of convenience and economy.
Because backstretehers have contact with the race horses immediately before and between races, they are in a position to administer drugs or apply mechanical devices (called “buzzers”) to the horses, both of which affect the speed of a horse and hence the outcome of a race. The Act forbids these practices. Ill.Ann.Stat. ch. 8, paras. 37-36, 37-37 (Smith-Hurd Supp. 1987). The Board and IDLE, which the legislature charged with the enforcement of the Act, Ill.Rev.Stat. ch. 8, para. 37-34 (1983), believe that warrantless searches of all backstretch areas, including the dormitories, and of licensees’ persons is the only effective way of enforcing the statutory prohibitions against the use of drugs and buzzers. Backstretch areas and licensees are searched when IDLE has received a “tip” or when irregularities are noted in a horse’s performance; searches are also performed at random. We have no reason to question the Board’s representations about the threat posed by drugs and buzzers and its need to take strong measures against them.
In this respect, the Act vests in the Board broad authority to regulate the horse-racing industry in Illinois. Specifically,
The Board, and any person or persons to whom it delegates this power, is vested with the power to enter the office, horse race track, facilities and other places of business of any organization licensee to determine whether there has been compliance with the provisions of this Act and its rules and regulations. *26Ill.Ann.Stat. ch. 8, para. 37-9(c) (Smith-Hurd Supp.1987). Pursuant to its rulemaking powers, the Board has promulgated Thoroughbred Rules 322 and 25.19 (the “Rules”), which employ identical language and read as follows:
(a) The Illinois Racing Board or the state steward investigating for violations of law or the Rules and Regulations of the Board, shall have the power to permit persons authorized by either of them to search the person, or enter and search the stables, rooms, vehicles, or other places within the track enclosure at which a meeting is held, or other tracks or places where horses eligible to race at said race meeting are kept, of all persons licensed by the Board, and of all employees and agents of any race track operator licensed by said Board; and of all vendors who are permitted by said race track operator to sell and distribute their wares and merchandise within the race track enclosure, in order to inspect and examine the personal effects or property on such persons or kept in such stables, rooms, vehicles, or other places as aforesaid. Each of such licensees, in accepting a license, does thereby irrevocably consent to such search as aforesaid and waive and release all claims or possible actions for damages that he may have by virtue of any action taken under this rule. Each employee of a licensed operator, in accepting his employment, and each vendor who is permitted to sell and distribute his merchandise within the race track enclosure, does thereby irrevocably consent to such search as aforesaid and waive and release all claims or possible actions for damages they may have by virtue of any action taken under this rule. Any person who refuses to be searched pursuant to this rule may have his license suspended or revoked.
(b) The Illinois Racing Board delegates the authority to conduct inspections and searches, under this rule, to the Chief Investigator of the Illinois Racing Board and to Special Agents of the Illinois Bureau of Investigation, or other designees of the Department of Law Enforcement assigned, from time to time, to assist the Chief Investigator in his duties.
The challenged searches were undertaken pursuant to this regulation.
The Act also empowers the Board to prescribe application forms and issue licenses to backstretchers. Ill.Ann.Stat. ch. 8, paras. 37-15, 37-20 (Smith-Hurd Supp. 1987). Prior to the entry of the preliminary injunction in this case, the license application form used by the Board quoted the text of the above Rules and conditioned the license’s issuance upon consent to the searches authorized by the Rules.
The material facts about the searches of the named plaintiffs are undisputed.1 Don Serpas, Raymond Johnson and Carl Waters are employed as grooms and live in residential quarters at Arlington Park Racetrack. Their residential quarters have been searched by IDLE agents; they have also been stopped and personally searched by IDLE agents within the race track enclosure. No evidence of crime was found during any of the challenged searches. The plaintiffs acknowledge that when they signed the license application forms, they consented to the searches. They also admit that they consented to each of the searches at the time it occurred. They claim, however, that they would not have consented to these warrantless searches if they had not been required to give consent in order to remain in a job as a backstretch-er.
On July 30, 1982, these three plaintiffs filed a complaint in the Northern District of Illinois, naming as defendants present and former members of the Board, the director of IDLE and certain unknown IDLE agents and seeking injunctive and declaratory relief. On September 24, 1982, they filed a motion for a preliminary injunction, which was granted in its entirety on *27June 16, 1983. This order of the district court enjoined the defendants from (1) conducting or authorizing searches of persons and residential quarters without a warrant or probable cause; (2) conducting or authorizing investigatory stops of backstretchers without a reasonable suspicion, based on articulable facts, that the backstretchers stopped were engaged in criminal activity; and (3) conditioning the issuance of occupation licenses to backstretchers upon consent to these searches. Memorandum Opinion and Order, Serpas v. Schmidt, No. 82-C-4715 (N.D.Ill. June 16, 1983) [Available on WESTLAW, DOT database].
On September 19, 1983, the trial court certified Serpas, Johnson and Waters as named representatives of a class consisting of all grooms, exercise persons and hotwalkers at Illinois racetracks. In August and October 1984, the parties filed cross-motions for summary judgment. The trial court filed a memorandum opinion, granting the plaintiffs’ motion and entering a permanent injunction on July 11, 1985. Memorandum Opinion, Serpas v. Schmidt, 621 F.Supp. 734 (N.D.Ill.1985). This appeal followed.2
A. Warrantless Searches of Dormitory Rooms
The Fourth Amendment protects against “unreasonable” searches and seizures. The reasonableness of a search depends upon a person’s expectation of privacy in the place to be searched, provided that that expectation is one that society is willing to recognize as “reasonable.” Katz v. United States, 389 U.S. 347, 361, 88 S.Ct. 507, 516, 19 L.Ed.2d 576 (1967) (Harlan, J., concurring). Appellants contend that the back-stretchers’ asserted expectation of privacy in their on-track dormitory rooms is not the sort of expectation that society recognizes as reasonable. They rely on historic state regulation of the horse-racing industry, the less than commodious quality of the on-track quarters and the backstretchers’ implied consent to the searches.
*28We have no doubt that horse racing is and ought to be a pervasively regulated industry. But a history of pervasive regulation of an industry is not by itself enough to render the warrant requirement superfluous. As we noted in Bionic Auto Parts and Sales, Inc. v. Fahner, 721 F.2d 1072, 1079 (7th Cir.1983),
the degree and extent of past regulation comprise but a part, albeit a substantial part, of a determination of a “reasonable expectation of privacy” under the Fourth Amendment. Otherwise, no protections at all would be appropriate in closely regulated industries. The Fourth Amendment requires that a determination of the “reasonableness” of the intrusion be made. Even in closely regulated industries, the inspection provisions still must be tailored to the state’s proper objectives, and they must minimize the dangers inherent in the unbridled exercise of administrative discretion.
It is certainly true, as appellants point out, that the Supreme Court has sanctioned warrantless searches of commercial premises in certain industries subject to longstanding governmental oversight. New York v. Burger, — U.S. -, 107 S.Ct. 2636, 96 L.Ed.2d 601 (1987) (junkyards); Donovan v. Dewey, 452 U.S. 594, 101 S.Ct. 2534, 69 L.Ed.2d 262 (1981) (mining); United States v. Biswell, 406 U.S. 311, 92 S.Ct. 1593, 32 L.Ed.2d 87 (1972) (firearms); Colonnade Catering Corp. v. United States, 397 U.S. 72, 90 S.Ct. 774, 25 L.Ed.2d 60 (1970) (alcoholic beverages). In each of these cases, however, an Act of Congress expressly authorized the terms and conditions of searches on specified premises. The rationale for not requiring a warrant in such a situation is that a statutory inspection program “in terms of the certainty and regularity of its application, provides a constitutionally adequate substitute for a warrant.” Dewey, 452 U.S. at 603, 101 S.Ct. at 2540. In that way, there is assurance that the individual’s privacy interest and the government’s interest in law enforcement are properly balanced. See Marshall v. Barlow’s, Inc., 436 U.S. 307, 321, 98 S.Ct. 1816, 1824, 56 L.Ed.2d 305 (1978) (“The reasonableness of a warrantless search ... will depend upon the specific enforcement needs and privacy guarantees of each statute.”).
The statutory authority claimed by the appellants for the searches challenged here states that the Board and its delegates are “vested with the power to enter the office, horse race track, facilities and other places of business” of any licensee to ensure compliance with the Racing Act. Ill.Ann.Stat. ch. 8, para. 37-9(c) (SmithHurd Supp.1987). Far from specifying the “terms and conditions” under which warrantless searches of dormitory rooms can be conducted, this statute does not even appear to authorize searches of these areas. Appellants contend that the dormitory rooms are “facilities” for purposes of the Racing Act. We agree with the district court that this is not a reasonable reading of the statutory language. The provision specifically lists a series of places, ending with the catch-all “other places of business.” This concluding phrase effectively defines the earlier listed places as places of business. The statute in no way suggests that a residence may be searched. We agree with the district court that these on-track dormitory rooms must be considered the backstretchers’ “homes” for Fourth Amendment purposes. Appellants point out that the rooms are very small and located either adjacent to or above the stables in the backstretch of the track. Further, they are only temporary lodgings and are accessible to track authorities by a master key. Nonetheless, they are exclusively residential, and lodgings as cramped, inhospitable or temporary have been considered residences by the courts. See Stoner v. California, 376 U.S. 483, 84 S.Ct. 889, 11 L.Ed.2d 856 (1964) (hotel rooms); McDonald v. United States, 335 U.S. 451, 69 S.Ct. 191, 93 L.Ed. 153 (1948) (rooming houses); Smyth v. Lubbers, 398 F.Supp. 777 (W.D.Mich.1975) (college dormitories). There is no evidence that the backstretchers conduct any of their business in the rooms; thus, cases such as United States v. Cerri, 753 F.2d 61 (7th Cir.), cert. denied, 472 U.S. 1017, 105 S.Ct. 3479, 87 L.Ed.2d 614 (1985), where petitioner con*29ducted his gun business out of his home, are distinguishable. Given the legal protection historically afforded the home by the Fourth Amendment, see, e.g., United States v. United States District Court, 407 U.S. 297, 313, 92 S.Ct. 2125, 2134, 32 L.Ed.2d 752 (1972) (“physical entry of the home is the chief evil against which the wording of the Fourth Amendment is directed”), we will not assume that the Illinois legislature meant to authorize warrantless residential searches unless it clearly stated this intention. Thus, because this statute does not even contemplate searches of residences, the statute does not provide any limitations on the discretion of track officials who wish to conduct searches of dormitory rooms. Cf. Burger, — U.S. -, 107 S.Ct. 2636 (Warrantless search of automobile junkyard pursuant to statute was upheld; statutory scheme limited time, place and scope of such inspections.).
Even without explicit statutory authorization for these searches, the appellants contend that sufficient certainty of application to serve as a substitute for a warrant can be found in the regulatory scheme taken as a whole. We disagree. To satisfy the “certainty and regularity” requirement, an “inspection program must define clearly what is to be searched, who can be searched, and the frequency of such searches.” Bionic Auto Parts, 721 F.2d at 1078. The rules under which the IDLE agents operated do not impose any meaningful limitations on their discretion. As the district court noted,
The searches may be focused or random and are not restricted to particular times nor restricted to particular areas or items in those areas which are in plain view____ [T]he agents may search plaintiffs’ living quarters and personal effects as extensively as they wish. Plainly, the agents have an unrestricted scope of search; requiring them to hand out receipts or consent forms does not affect or limit the agent’s discretion to undertake an exhaustive search of every personal effect in an individual’s room.
Serpas v. Schmidt, supra, at 11-12. The regulatory scheme here thus falls short of adequately substituting for a warrant. As the Supreme Court explained in rejecting a warrantless search scheme in Camara v. Municipal Court, 387 U.S. 523, 532-33, 87 S.Ct. 1727, 1732-33, 18 L.Ed.2d 930 (1967), “[t]his is precisely the discretion to invade private property which we have consistently circumscribed by a requirement that a disinterested party warrant the need to search.”
There is no reason to doubt that drugs and mechanical devices pose major threats to the integrity of the horse racing industry. Nor do we question the reality of the Board’s concerns about protecting horse racing without broad powers of surveillance over backstretchers and others. But the Fourth Amendment requires regularity of application and an impartial assessment of reasonableness, and neither the controlling statute nor the regulations in this case impose any restrictions on the conduct of warrantless searches of residences. Hence, we agree with the district court that neither the statute nor the regulatory scheme here is sufficient to except these searches from the general rule that searches conducted without the safeguard of a warrant are unreasonable and violate the Fourth Amendment, see Johnson v. United States, 333 U.S. 10, 13-14, 68 S.Ct. 367, 368-369, 92 L.Ed. 436 (1948).
Finally, the appellants argue that the backstretchers impliedly consented to the searches by accepting occupation licenses conditioned upon compliance with Rules 322 and 25.19. Conditioning the receipt of a benefit, such as employment, on the relinquishment of a right that one would otherwise have is not per se unconstitutional. See, e.g., Snepp v. United States, 444 U.S. 507, 509 n. 3, 100 S.Ct. 763, 765 n. 3, 62 L.Ed.2d 704 (1980); United States Civil Serv. Comm’n v. National Ass’n of Letter Carriers, 413 U.S. 548, 567, 93 S.Ct. 2880, 2891, 37 L.Ed.2d 796 (1973). The race track employees consented to the searches based on a regulatory program that required them to give their consent as a condition of employment. As we have already found, however, the regulations were not authorized by statute and were *30unconstitutional because neither the regulations nor the governing statute confined the discretion of the state officials conducting the searches. Thus, the validity of the employees' consent was vitiated by the fact that it was premised on the existence of the otherwise unauthorized and unconstitutional regulations.
B. Warrantless Searches of the Back-stretchers
The district court also enjoined the Board and IDLE’s practice of conducting warrantless stops and searches of the back-stretchers’ persons within the race track enclosure. Appellants have not suggested that we should analyze the personal searches any differently from the residential searches, and we, too, think that the same rules apply. Like searches of property, searches of the person are generally impermissible absent a warrant issued upon a determination of probable cause. New York v. Belton, 453 U.S. 454, 457, 101 S.Ct. 2860, 2862, 69 L.Ed.2d 768 (1981); Mary Beth G. v. City of Chicago, 723 F.2d 1263, 1268 (7th Cir.1983). The deficiencies we have noted in the statute and regulatory scheme apply equally to these personal searches, and the arguments based upon consent are equally unpersuasive in this context.3 Cf Shoemaker v. Handel, 795 F.2d 1136, 1143 (3d Cir.1986) (regulatory scheme that subjected jockeys to breathalyzer and urine tests was upheld against a Fourth Amendment challenge, in part, because discretion of officials conducting such searches was appropriately circumscribed by regulation), cert. denied, — U.S. -, 107 S.Ct. 577, 93 L.Ed.2d 580 (1986).
As we have noted, we are certainly not unsympathetic to the appellants’ argument that extraordinary surveillance procedures are necessary to preserve the integrity of horse racing. The simple fact is, however, that the Illinois statute and regulations fall far short of providing an adequate basis for the extraordinary procedures undertaken here.
For the foregoing reasons, the judgment of the district court is Affirmed.
. The affidavits submitted by the parties differed in some of the details of the searches. The district court did not consider any of these disputes material. See Memorandum Opinion, Serpas v. Schmidt, No. 82-C-4715 (N.D.Ill. June 16, 1983), at 2 n. 2 [Available on WESTLAW, DCT database]. The appellants do not contest before this court the propriety of deciding the question presented to the district court by summary judgment.
. After oral argument we asked the parties to provide us with additional briefing on the question whether we should abstain and permit the Illinois courts to rule on the state law issues in the case, thus arguably mooting the federal constitutional questions. See Railroad Commission of Texas v. Pullman Co., 312 U.S. 496, 61 S.Ct. 643, 85 L.Ed. 971 (1941). This question was first raised at oral argument in the course of questioning by the panel.
After examining the supplemental briefs, we have concluded that abstention is not appropriate in this case. As the dissent correctly points out, this circuit has held that it might be proper in some cases for an appellate court to order abstention even though neither party had raised this issue. See Waldron v. McAtee, 723 F.2d 1348, 1351 (7th Cir.1983). However, we do not think that it would be appropriate for us to order abstention sua sponte here. In the controversy before us, the federal courts are not "the lone guardian of the state’s sovereign place under the Constitution,” infra, p. 32; the defendants are state officials who raised no objection to having the claims against them litigated in federal court until this court itself raised the abstention issue. See Houston v. Hill, — U.S. -,-n. 16, 107 S.Ct. 2502, 2512 n. 16, 96 L.Ed.2d 398 (1987) (failure of defendant city to raise possibility of abstention until after it had lost on the merits before an appellate court undercut the force of the city’s argument); Mazanec v. North Judson-San Pierre School Corp., 763 F.2d 845, 848-49 (7th Cir.1985) (State defendants did not request abstention until the end of trial; this is "an independent argument against abstention.” "[I]f the responsible state officials are willing to litigate the case in federal court, that court does not have to force it back into state court.”) (emphasis in original) (citation omitted). -
In addition, there is a presumption in this circuit against abstaining once a case has gone to trial; this presumption holds at least "where neither party requested abstention before trial." Mazanec, 763 F.2d at 847. The district court in this case granted the plaintiffs’ motion, for a preliminary injunction in 1983 and enjoined the searches permanently in 1985 on plaintiffs’ motion for summary judgment. The defendants did not raise an abstention issue during any of these proceedings, nor did they raise it before us. The dissent contends that Mazanec is not applicable to this case because Mazanec states that the presumption against abstaining may be rebutted if the state statute at issue could be interpreted narrowly and thus survive a constitutional challenge. Infra, p. 32 n. 3. We believe, however, that the resolution of the constitutional issues in this case might well be necessary even if a state court found that the Act did not authorize the Rules. If the plaintiffs had validly consented to the searches or if they had a reduced expectation of privacy, it certainly could be argued that the defendants would not have needed an independent basis of authority under state law to conduct the searches. Thus, abstention might not produce a state law result which would be dispositive of the claims under the federal Constitution.
. Appellants argue that we are bound to reverse the district court on the authority of the Supreme Court’s summary affirmance of the unpublished decision of a three-judge panel in Wilkey v. Illinois Racing Board, No. 74-C-3524 (N.D.Ill.1975), aff'd, 423 U.S. 802, 96 S.Ct. 9, 46 L.Ed.2d 23 (1975). In that case the court upheld a Board rule that authorized a personal search of a licensee veterinarian in the backstretch of the track. Unpublished opinions have no precedential effect in this circuit. See Circuit Rule 35. Summary affirmances by the Supreme Court do have some precedential effect, although they affirm the lower court’s judgment only and not its rationale. Summary affirmances "prevent lower courts from coming to opposite conclusions on the precise issues presented and necessarily decided by those actions.” Mandel v. Bradley, 432 U.S. 173, 176, 97 S.Ct. 2238, 2240, 53 L.Ed.2d 199 (1977). Wilkey involved a challenge by a Board-licensed veterinarian to Rule 322. He had lost his license after refusing to consent to a personal search. Precedential effect "is to be assessed in light of all of the facts of the case," id. at 177, 97 S.Ct. at 2241, and Wilkey is distinguishable, notably in that the Board argued that there was probable cause to search Wilkey. Further, we note that the Court affirmed Wilkey before its more recent pronouncements on the limits of the administrative search exception, Marshall v. Barlow’s, Inc., supra, and Donovan v. Dewey, supra. In light of these factors, we do not think we are bound by the Supreme Court’s summary affirmance in Wilkey.