 The restrictions of time, place, and manner can be allowed if they are (a) narrowly tailored (b) serve a substantial governmental interest and (c) there are alternative channels to communicate the information.Contrary to the conclusion of the Court of Appeals, the foregoing analysis demonstrates that the Park Service regulation is sustainable under the four-factor standard of "United States v. O'Brien", 391 U.S. 367 (1968), for validating a regulation of expressive conduct, which, in the last analysis is little, if any, different from the standard applied to time, place, or manner restrictions.Justice White also makes clear that in the view of the majority the act of sleeping holds little value in being considered an act of expression.