The activities of the police, like those of other public officials, are subject to public scrutiny...Videotaping is a legitimate means of gathering information for public dissemination and can often provide cogent evidence, as it did in this case. In sum, there can be no doubt that the free speech clause of the Constitution protected Robinson as he videotaped the defendants on October 23, 2002....Moreover, to the extent that the troopers were restraining Robinson from making any future videotapes and from publicizing or publishing what he had filmed, the defendants' conduct clearly amounted to an unlawful prior restraint upon his protected speech....We find that defendants are liable under § 1983 for violating Robinson's Fourth Amendment right to be protected from an unlawful seizure...