delivered the opinion of the Court.
Johnnie Cochran brought a state-law defamation action against petitioner Ulysses Tory. The state trial court determined that Tory (with the help of petitioner Ruth Craft and others) had engaged in unlawful defamatory activity. . It found, for example, that Tory, while claiming falsely that Cochran owed him money, had complained to the local bar association, had written Cochran threatening letters demanding $10 million, had picketed Cochran’s office holding up signs containing various insults and obscenities; and, with a group of associates, had pursued Cochran while chanting similar threats and insults. App. 88,40-41. The court concluded that Tory’s claim that Cochran owed him money was without foundation, that Tory engaged in a continuous pattern of libelous and slanderous activity, and that Tory had *736used false and defamatory speech to “coerce” Cochran into paying “amounts of money to which Tory was not entitled” as a “tribute” or a “premium” for “desisting” from this libelous and slanderous activity. Id., at 39, 42-48.
After noting that Tory had indicated that he would continue to engage in this activity in the absence of a court order, the Superior Court issued a permanent injunction. The injunction, among other things, prohibited Tory, Craft, and their “agents” or “representatives” from “picketing,” from “displaying signs, placards or other written or printed material,” and from “orally uttering statements” about Johnnie L. Cochran, Jr., and about Cochran’s law firm in “any public forum.” Id., at 34.
Tory and Craft appealed. The California Court of Appeal affirmed. Tory and Craft then filed a petition for a writ of certiorari, raising the following question:
“Whether a permanent injunction as a remedy in a defamation action, preventing all future speech about an admitted public figure, violates the First Amendment.” Pet. for Cert. i.
After oral argument, Cochran’s counsel informed the Court of Johnnie Cochran’s recent death. Counsel also moved to substitute Johnnie Cochran’s widow, Sylvia Dale Mason Cochran, as respondent, and suggested that we dismiss the case as moot. Tory and Craft filed a response agreeing to the substitution of Ms. Cochran. But they denied that the case was moot.
We agree with Tory and Craft that the case is not moot. Despite Johnnie Cochran’s death, the injunction remains in effect. Nothing in its language says to the contrary. Cochran’s counsel tells us that California law does not recognize a “cause of action for an injury to the memory of a deceased person’s reputation,” see Kelly v. Johnson Pub. Co., 160 Cal. App. 2d 718, 325 P. 2d 659 (1958), which circumstance, counsel believes, “moots” a “'portion” of the injunc*737tion (the portion “personal to Cochran”). Respondent’s Suggestion of Death, etc., 4 (emphasis added). But counsel adds that “[t]he [injunction continues to be necessary, valid and enforceable.” Id., at 9. The parties have not identified, nor have we found, any source of California law that says the injunction here automatically becomes invalid upon Cochran’s death, not even the portion personal to Cochran. Counsel also points to the “value of” Cochran’s “law practice” and adds that his widow has an interest in enforcing the injunction. Id., at 11-12. And, as we understand California law, a person cannot definitively know whether an injunction is legally void until a court has ruled that it is. See Mason v. United States Fidelity & Guaranty Co., 60 Cal. App. 2d 587, 591, 141 P. 2d 475, 477-478 (1943) (“[W]here the party served believes” a court order “invalid he should take the proper steps to have it dissolved”); People v. Gonzalez, 12 Cal. 4th 804, 818, 910 P. 2d 1366, 1375 (1996) (“[A] person subject to a court’s injunction may elect whether to challenge the constitutional validity of the injunction when it is issued, or to reserve that claim until a violation of the injunction is charged as a contempt of court”). Given the uncertainty of California law, we take it as a given that the injunction here continues significantly to restrain petitioners’ speech, presenting an ongoing federal controversy. See, e. g., Dombrowski v. Pfister, 380 U. S. 479, 486-487 (1965); NAACP v. Button, 371 U. S. 415, 432-433 (1963). Consequently, we need not, and we do not, dismiss this case as moot. Cf. Firefighters v. Stotts, 467 U. S. 561, 569 (1984) (case not moot in part because it appears from “terms” of the injunction that it is “still in force” and “unless set aside must be complied with”).
At the same time, Johnnie Cochran’s death makes it unnecessary, indeed unwarranted, for us to explore petitioners’ basic claims, namely, (1) that the First Amendment forbids the issuance of a permanent injunction in a defamation case, at least when the plaintiff is a public figure, and (2) that *738the injunction (considered prior to Cochran’s death) was not properly tailored and consequently violated the First Amendment. See Brief for Petitioners ii, iii. Rather, we need only point out that the injunction, as written, has now lost its underlying rationale. Since picketing Cochran and his law offices while engaging in injunction-forbidden speech could no longer achieve the objectives that the trial court had in mind (i. e., coercing Cochran to pay a “tribute” for desisting in this activity), the grounds for the injunction are much diminished, if they have not disappeared altogether. Consequently the injunction, as written, now amounts to an overly broad prior restraint upon speech, lacking plausible justification. See Nebraska Press Assn. v. Stuart, 427 U. S. 539, 559 (1976) (“[P]rior restraints on speech and publication are the most serious and the least tolerable infringement on First Amendment rights”); Pittsburgh Press Co. v. Pittsburgh Comm’n on Human Relations, 413 U. S. 376, 390 (1973) (a prior restraint should not “swee[p]” any “more broadly than necessary”). As such, the Constitution forbids it. See Carroll v. President and Comm’rs of Princess Anne, 393 U. S. 175, 183-184 (1968) (An “order” issued in “the area of First Amendment rights” must be “precis[e]” and narrowly “tailored” to achieve the “pin-pointed objective” of the “needs of the case”); see also Board of Airport Comm’rs of Los Angeles v. Jews for Jesus, Inc., 482 U. S. 569, 575, 577 (1987) (regulation prohibiting “all 'First Amendment activities’ ” substantially overbroad).
We consequently grant the motion to substitute Sylvia Dale Mason Cochran for Johnnie Cochran as respondent. We vacate the judgment of the California Court of Appeal, and we remand the case for proceedings not inconsistent with this opinion. If, as the Cochran supplemental brief suggests, injunctive relief may still be warranted, any appropriate party remains free to ask for such relief. We express no view on the constitutional validity of any such new re*739lief, tailored to these changed circumstances, should it be entered.
It is so ordered.