dissenting.
The pertinent phrasing of the Fourth Amendment— “The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated” — is virtually in haec verba as Art. I, § 19, of the California Constitution— “The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable seizures and searches, shall not be violated.” The California Supreme Court has reached a conclusion under Art. I, § 19, in the same factual situation, contrary to that reached by the Court today under the Fourth Amendment.1 I dissent because in my view the California Supreme Court correctly interpreted the relevant constitutional language.
In Burrows v. Superior Court, 13 Cal. 3d 238, 529 P. 2d 590 (1974), the .question was whether bank statements or copies thereof relating to an accused’s bank accounts obtained by the sheriff and prosecutor without *448benefit of legal process,2 but with the consent of the bank, were acquired as a result of an illegal search and seizure. The California Supreme Court held that the accused had a reasonable expectation of privacy in his bank statements and records, that the voluntary relinquishment of such records by the bank at the request of the sheriff and prosecutor did not constitute a valid consent by the accused, and that the acquisition by the officers of the records therefore was the result of an illegal search and seizure. In my view the same conclusion, for the reasons stated by the California Supreme Court, is compelled in this case under the practically identical phrasing of the Fourth Amendment. Addressing the threshold question whether the accused's right of privacy was invaded, and relying in part on the decision of the Court of Appeals in this case, Mr. Justice Mosk stated in his excellent opinion for a unanimous court:
“It cannot be gainsaid that the customer of a bank expects that the documents, such as checks, which he transmits to the bank in the course of his business operations, will remain private, and that such an expectation is reasonable. The prosecution concedes as much, although it asserts that this expecta*449tion. is not constitutionally cognizable. Representatives of several banks testified at the suppression hearing that information in their possession regarding a customer’s account is deemed by them to be confidential.
“In the present case, although the record establishes that copies of petitioner’s bank statements rather than of his checks were provided to the officer, the distinction is not significant with relation to petitioner’s expectation of privacy. That the bank alters the form in which it records the information transmitted to it by the depositor to show the receipt and disbursement of money on a bank statement does not diminish the depositor’s anticipation of privacy in the matters which he confides to the bank. A bank customer’s reasonable expectation is that, absent compulsion by legal process, the matters he reveals to the bank will be utilized by the bank only for internal banking purposes. Thus, we hold petitioner had a reasonable expectation that the bank would maintain the confidentiality of those papers which originated with him in check form and of the bank statements into which a record of those same checks had been transformed pursuant to internal bank practice.
“The People assert that no illegal search and seizure occurred here because the bank voluntarily provided the statements to the police, and the bank rather than the police conducted the search of its records for papers relating to petitioner’s accounts. If, as we conclude above, petitioner has a reasonable expectation of privacy in the bank statements, the voluntary relinquishment of such records by the bank at the request of the police does not constitute *450a valid consent by this petitioner. ... It is not the right of privacy of the bank but of the petitioner which is at issue, and thus it would be untenable to conclude that the bank, a neutral entity with no significant interest in the matter, may validly consent to an invasion of its depositors’ rights. However, if the bank is not neutral, as for example where it is itself a victim of the defendant’s suspected wrongdoing, the depositor’s right of privacy will not prevail.
“Our rationale is consistent with the recent decision of United States v. Miller (5th Cir. 1974) 500 F. 2d 751. In Miller, the United States Attorney, without the defendant’s knowledge, issued subpoenas to two banks in which the defendant maintained accounts, ordering the production of 'all records of accounts’ in the name of the defendant. The banks voluntarily provided the government with copies of the defendant’s checks and a deposit slip; these items were introduced into evidence at the trial which led to his conviction. The circuit court reversed the conviction. It held that the defendant’s rights under the Fourth Amendment were violated by the search because the subpoena was issued by the United States Attorney rather than by a court or grand jury, and the bank's voluntary compliance with the subpoena was irrelevant since it was the depositor’s right to privacy which was threatened by the disclosure.
“We hold that any bank statements or copies thereof obtained by the sheriff and prosecutor without the benefit of legal process were acquired as the result of an illegal search and seizure (Cal. Const., art. I, § 13), and that the trial court should have granted the motion to suppress such documents.
*451“The underlying dilemma in this and related cases is that the bank, a detached and disinterested entity, relinquished the records voluntarily. But that circumstance should not be crucial. For all practical purposes, the disclosure by individuals or business firms of their financial affairs to a bank is not entirely volitional, since it is impossible to participate in the economic life of contemporary society without maintaining a bank account. In the course of such dealings, a depositor reveals many aspects of his personal affairs, opinions, habits and associations. Indeed, the totality of bank records provides a virtual current biography. While we are concerned in the present case only with bank statements, the logical extension of the contention that the bank’s ownership of records permits free access to them by any police officer extends far beyond such statements to checks, savings, bonds, loan applications, loan guarantees, and all papers which the customer has supplied to the bank to facilitate the conduct of his financial affairs upon the reasonable assumption that the information would remain confidential. To permit a police officer access to these records merely upon his request, without any judicial control as to relevancy or other traditional requirements of legal process, and to allow the evidence to be used in any subsequent criminal prosecution against a defendant, opens the door to a vast and unlimited range of very real abuses of police power.
“Cases are legion that condemn violent searches and invasions of an individual’s right to the privacy of his dwelling. The imposition upon privacy, although perhaps not so dramatic, may be equally devastating when other methods are employed. Development of photocopying machines, electronic computers and other sophisticated instruments have *452accelerated the ability of government to intrude into areas which a person normally chooses to exclude from prying eyes and inquisitive minds. Consequently judicial interpretations of the reach of the constitutional protection of individual privacy must keep pace with the perils created by these new devices.” 13 Cal. 3d, at 243-248, 529 P. 2d, at 593-596 (footnote omitted).
The California Supreme Court also addressed the question of the relevance of California Bankers Assn. v. Shultz, 416 U. S. 21 (1974). In my view, for the reasons stated in Burrows, the decision of the Court of Appeals under review today, is in no way inconsistent with California Bankers.3 The California Supreme Court said:
“[California Bankers] held, in a six-three decision, that the bank’s rights under the Fourth Amendment were not abridged by the regulation, and that the depositor plaintiffs lacked standing to challenge the reporting requirement because there was no showing that they engaged in the type of transaction to which the regulation referred.
“The concurring views of two justices who provided the necessary votes to create a majority are of particular interest. Justice Powell’s opinion, joined by Justice Blackmun [416 U. S., at 78] makes clear that a significant extension of the reporting requirement would pose substantial constitutional questions, and that concurrence with the *453majority was based upon the provisions of the act as narrowed by the regulations. He wrote, 'In their full reach, the reports apparently authorized by the open-ended language of the Act touch upon intimate areas of an individual’s personal affairs. Financial transactions can reveal much about a person’s activities, associations, and beliefs. At some point, governmental intrusion upon these areas would implicate legitimate expectations of privacy. Moreover, the potential for abuse is particularly acute where, as here, the legislative scheme permits access to this information without invocation of the judicial process. In such instances, the important responsibility for balancing societal and individual interests is left to unreviewed executive discretion, rather than the scrutiny of a neutral magistrate. United States v. United States District Court, 407 U. S. 297, 316— 317.’ [416 U. S., at 78-79.]
“Justices Douglas and Marshall dissented on the ground that the act violated the Fourth Amendment. Justice Brennan also filed a dissent, stating that the recordkeeping and reporting requirements of the act constituted an impermissibly broad grant of power to the Secretary.
“. . . [T]he only federal case decided after Shultz and directly confronting the issue of the depositor’s rights is entirely consistent with the views we have set forth above. . . . Miller holds that Shultz may not be interpreted as 'proclaiming open season on personal bank records’ or as permitting the government to circumvent the Fourth Amendment by first requiring banks to copy their depositors’ checks and then calling upon the banks to allow inspection of those copies without appropriate legal process.” 13 Cal. 3d, at 246-247, 529 P. 2d, at 595-596 (footnote omitted).
*454I would therefore affirm the judgment of the Court of Appeals. I add only that Burrows strikingly illustrates the emerging trend among high state courts of relying upon state constitutional protections of individual liberties4 — protections pervading counterpart provisions of *455the United States Constitution, but increasingly being ignored by decisions of this Court. For the most recent examples in this Court, but only in the privacy and Fourth Amendment areas, see, e. g., Kelley v. Johnson, ante, p. 238; Doe v. Commonwealth’s Atty., post, p. 901; Paul v. Davis, 424 U. S. 693 (1976); United States v. Watson, 423 U. S. 411 (1976).
The expectation of privacy relied upon by respondent to support his Fourth Amendment claim is similar to that rejected as to similar documents in Couch v. United States, 409 U. S. 322 (1973). But in Couch the taxpayer had delivered the documents to her accountant for preparation of income tax .returns “knowing that mandatory disclosure of much of the information therein is required in an income tax return.” Id., at 335; see id., at 337 (Brennan, J., concurring). In contrast, in the instant case the banks were obliged only to respond to lawful process, California Bankers Assn. v. Shultz, 416 U. S. 21, 52-54 (1974), and had no obligation to disclose the information voluntarily. The expectation of privacy asserted in Fisher v. United States, ante, p. 391, is distinguishable on similar grounds.
The Court distinguishes Burrows on the ground that it involved no legal process, while the instant case involves legal process in the form of subpoenas duces tecum. Ante, at 445 n. 7. But the Court also states that the Fourth Amendment issue does not turn on whether the subpoenas were defective. Ante, at 441 n. 2.
In any event, for present purposes I would accept the Court of Appeals’ conclusion that the subpoenas in this case were defective. Moreover, although not relied upon by the Court of Appeals, neither the bank nor the Government notified respondent of the disclosure of his records to the Government. In my view, the absence of such notice is not just “unattractive," ante, at 443 n. 5; a fatal constitutional defect inheres in a process that omits provision for notice to the bank customer of an invasion of his protected Fourth Amendment interest.
I continue to believe that the reporting and recordkeeping requirements of the Bank Secrecy Act are unconstitutional. California Bankers Assn. v. Shultz, 416 U. S., at 91 (Brennan, J., dissenting). But I disagree with the Court’s reasoning in this case even assuming the constitutionality of the Act, and therefore it is unnecessary for me to rely on the infirmities inherent in the Act.
See, e. g., cases cited in Baxter v. Palmigiano, ante, at 339, and n. 10 (Brennan, J., dissenting); Michigan v. Mosley, 423 U. S. 96, 120-121 (1975) (Brennan, J., dissenting). See also Wilkes, The New Federalism in Criminal Procedure: State Court Evasion of the Burger Court, 62 Ky. L. J. 421 (1974); Wilkes, More on the New Federalism in Criminal Procedure, 63 Ky. L. J. 873 (1975); Falk, The State Constitution: A More Than “Adequate” Nonfederal Ground, 61 Calif. L. Rev. 273 (1973); Project Report: Toward an Activist Role for State Bills of Rights, 8 Harv. Civ. Rights-Civ. Lib. L. Rev. 271 (1973). In the past, it might have been safe for counsel to raise only federal constitutional issues in state courts, but the risks of not raising state-law questions are increasingly substantial, as revealed by a colloquy during argument in Michigan v. Mosley, supra:
“QUESTION: Why can’t you argue all of this as being contrary to the law and the Constitution of the State of Michigan?
“MR. ZIEMBA: I can because we have the same provision in the Michigan Constitution of 1963 as we have in the Fifth Amendment of the Federal Constitution, certainly.
“QUESTION: Well, you argued the whole thing before.
“MR. ZIEMBA: In the Court of Appeals?
“QUESTION: Yes.
"MR. ZIEMBA: I really did not touch upon — I predicated my entire argument on the Federal Constitution, I must admit that. I did not mention the equivalent provision of the Michigan Constitution of 1963, although I could have. And I may assure this Court that at every opportunity in the future, I shall.
“[Laughter.]
“QUESTION: But you hope you don’t have that opportunity in this case.
“MR. ZIEMBA: That’s right.” Tr. of Oral Arg. 43-44 (O. T. 1975, No. 74-653).
It would be unwise for counsel to rely on state courts to consider state-law questions sua sponte. But see State v. Johnson, 68 N. J. 349, 346 A. 2d 66 (1975).