all parts of a school building or its immediate environs for his unlimited expressive purposes. Expressive activity could certainly be restricted, but only if the forbidden conduct "materially disrupts classwork or involves substantial disorder or invasion of the rights of others." Id., at 513. The wearing of armbands was protected in Tinker because the students "neither interrupted school activities nor sought to intrude in the school affairs or the lives of others. They caused discussion outside of the classrooms, but no interference with work and no disorder." Id., at 514. Compare Burnside v. Byars, 363 F. 2d 744 (CA5 1966), and Butts v. Dallas Ind. School District, 436 F. 2d 728 (CA5 1971), with Blackwell v. Issaquena County Board of Education, 363 F. 2d 749 (CA5 1966).

Just as Tinker made clear that school property may not be declared off limits for expressive activity by students, we think it clear that the public sidewalk adjacent to school grounds may not be declared off limits for expressive activity by members of the public. But in each case, expressive activity may be prohibited if it "materially disrupts classwork or involves substantial disorder or invasion of the rights of others." Tinker v. Des Moines School District, 393 U. S., at 513.39 We would be ignoring reality if we did not recognize that the public schools in a community are important institutions, and are often the focus of significant grievances.40 Without interfering with normal school activi

39 In Tinker we recognized that the principle of that case was not limited to expressive activity within the school building itself. Id., at 512 n. 6, 513-514. See Esteban v. Central Missouri State College, 415 F. 2d 1077 (CA8 1969) (Blackmun, J.), cert. denied, 398 U. S. 965 (1970); Jones v. Board of Regents, 436 F. 2d 618 (CA9 1970); Hammond v. South Carolina State College, 272 F. Supp. 947 (SC 1967), cited in Tinker.

40 Cf. Thornhill v. Alabama, 310 U. S., at 102. It goes without saying that "one is not to have the exercise of his liberty of

rowly tailored to further the State's legitimate interest.35 Access to the "streets, sidewalks, parks, and other similar public places . . . for the purpose of exercising [First Amendment rights] cannot constitutionally be denied broadly. . . ." 36 Free expression "must not, in the guise of regulation, be abridged or denied.” 37

In light of these general principles, we do not think that Rockford's ordinance is an unconstitutional regulation of activity around a school. Our touchstone is Tinker v. Des Moines School District, 393 U. S. 503 (1969), in which we considered the question of how to accommodate First Amendment rights with the "special characteristics of the school environment." Id., at 506. Tinker held that the Des Moines School District could not punish students for wearing black armbands to school in protest of the Vietnam war. Recognizing that

'wide exposure to . . . robust exchange of ideas'” is an "important part of the educational process" and should be nurtured, id., at 512, we concluded that free expression could not be barred from the school campus. We made clear that "undifferentiated fear or apprehension of disturbance is not enough to overcome the right to freedom of expression," id., at 508,38 and that particular expressive activity could not be prohibited because of a "mere desire to avoid the discomfort and unpleasantness that always accompany an unpopular viewpoint," id., at 509. But we nowhere suggested that students, teachers, or anyone else has an absolute constitutional right to use

35 De Jonge v. Oregon, 299 U. S. 353, 364-365 (1937); Lovell v. Griffin, 303 U. S., at 451; Schneider v. State, 308 U. S., at 164; Cantwell v. Connecticut, 310 U. S., at 307; Cox v. Louisiana, 379 U. S., at 562-564; Davis v. Francois, 395 F. 2d 730 (CA5 1968). Cf. Shelton v. Tucker, 364 U. S. 479, 488 (1960); NAACP v. Button, 371 U. S. 415, 438 (1963).

36 Food Employees v. Logan Valley Plaza, 391 U. S., at 315. 37 Hague v. CIO, 307 U. S., at 516.

38 Cf. Hague v. CIO, supra, at 516.

might put an intolerable burden on the essential flow of traffic, and for that reason could be prohibited. Cox v. Louisiana, 379 U. S., at 554. If overamplified loudspeakers assault the citizenry, government may turn them down. Kovacs v. Cooper, 336 U. S. 77 (1949); Saia v. New York, 334 U. S. 558, 562 (1948). Subject to such reasonable regulation, however, peaceful demonstrations in public places are protected by the First Amendment.31 Of course, where demonstrations turn violent, they lose their protected quality as expression under the First Amendment.32

The nature of a place, "the pattern of its normal activities, dictate the kinds of regulations of time, place, and manner that are reasonable." 33 Although a silent vigil may not unduly interfere with a public library, Brown v. Louisiana, 383 U. S. 131 (1966), making a speech in the reading room almost certainly would. That same speech should be perfectly appropriate in a park. The crucial question is whether the manner of expression is basically incompatible with the normal activity of a particular place at a particular time. Our cases make clear that in assessing the reasonableness of a regulation, we must weigh heavily the fact that communication is involved; 34 the regulation must be nar

31 Police Department of Chicago v. Mosley, ante, at 95-96, and cases cited.

32 See generally T. Emerson, The System of Freedom of Expression 328-345 (1970).

33 Wright, The Constitution on the Campus, 22 Vand. L. Rev. 1027, 1042 (1969). Cf. Cox v. Louisiana, 379 U. S. 559 (1965); Adderley v. Florida, 385 U. S. 39 (1966); Food Employees v. Logan Valley Plaza, 391 U. S. 308 (1968); Tinker v. Des Moines School District, 393 U. S. 503 (1969).

34 E. g., Schneider v. State, 308 U. S. 147 (1939); Talley v. California, 362 U. S. 60 (1960); Saia v. New York, 334 U. S., at 562; Cox v. New Hampshire, 312 U. S., at 574; Hague v. CIO, 307 U. S., at 516. See generally Kalven, The Concept of the Public Forum: Cox v. Louisiana, 1965 Sup. Ct. Rev. 1.

whether the ordinance sweeps within its prohibitions what may not be punished under the First and Fourteenth Amendments. Specifically, appellant contends that the Rockford ordinance unduly interferes with First and Fourteenth Amendment rights to picket on a public sidewalk near a school. We disagree.

"In considering the right of a municipality to control the use of public streets for the expression of religious [or political] views, we start with the words of Mr. Justice Roberts that 'Wherever the title of streets and parks may rest, they have immemorially been held in trust for the use of the public and, time out of mind, have been used for purposes of assembly, communicating thoughts between citizens, and discussing public questions.' Hague v. CIO, 307 U. S. 496, 515 (1939)." Kunz v. New York, 340 U. S. 290, 293 (1951). See Shuttlesworth v. Birmingham, 394 U. S. 147, 152 (1969). The right to use a public place for expressive activity may be restricted only for weighty reasons.

Clearly, government has no power to restrict such activity because of its message.29 Our cases make equally clear, however, that reasonable "time, place and manner" regulations may be necessary to further significant governmental interests, and are permitted.30 For example, two parades cannot march on the same street simultaneously, and government may allow only one. Cox v. New Hampshire, 312 U. S. 569, 576 (1941). A demonstration or parade on a large street during rush hour

29 Police Department of Chicago v. Mosley, ante, p. 92.

30 Cox v. New Hampshire, 312 U. S. 569, 575-576 (1941); Kunz v. New York, 340 U. S., at 293-294; Poulos v. New Hampshire, 345 U. S. 395, 398 (1953); Cox v. Louisiana, 379 U. S., at 554-555; Cox v. Louisiana, 379 U. S. 559 (1965); Adderley v. Florida, 385 U. S. 39, 46-48 (1966); Food Employees v. Logan Valley Plaza, 391 U. S. 308, 320-321 (1968); Shuttlesworth v. Birmingham, 394 U. S. 147 (1969).

"willfully" done. 24 "Undesirables" or their "annoying" conduct may not be punished. The ordinance does not permit people to "stand on a public sidewalk . . . only at the whim of any police officer." 25 Rather, there must be demonstrated interference with school activities. As always, enforcement requires the exercise of some degree of police judgment, but, as confined, that degree of judgment here is permissible. The Rockford City Council has made the basic policy choices, and has given fair warning as to what is prohibited. "[T]he ordinance defines boundaries sufficiently distinct" for citizens, policemen, juries, and appellate judges.26 It is not impermissibly vague.

B. Overbreadth

A clear and precise enactment may nevertheless be "overbroad" if in its reach it prohibits constitutionally protected conduct.27 Although appellant does not claim that, as applied to him, the antinoise ordinance has punished protected expressive activity, he claims that the ordinance is overbroad on its face. Because overbroad laws, like vague ones, deter privileged activity, our cases firmly establish appellant's standing to raise an overbreadth challenge.28 The crucial question, then, is

24 Tracking the complaint, the jury verdict found Grayned guilty of "[w]ilfully causing diversion of good order of public school in session, in that while on school grounds and while school was in session, did wilfully make and assist in the making of a diversion which tended to disturb the peace and good order of the school session and class thereof."

25 Shuttlesworth v. Birmingham, 382 U. S., at 90.

26 Chicago v. Fort, 46 Ill. 2d 12, 16, 262 N. E. 2d 473, 476 (1970), a case cited in the opinion below.

27 See Zwickler v. Koota, 389 U. S. 241, 249-250 (1967), ard cases cited.

28 E. g., Gooding v. Wilson, 405 U. S. 518 (1972); Coates v. Cincinnati, 402 U. S., at 616; Dombrowski v. Pfister, 380 U. S., at 486, and cases cited; Kunz v. New York, 340 U. S. 290 (1951).