The majority of the Court, according to Justice William Brennan, agreed with Johnson and held that flag burning constitutes a form of "symbolic speech" that is protected by the First Amendment. The majority noted that freedom of speech protects actions that society may find very offensive, but society's outrage alone is not justification for suppressing free speech.
In particular, the majority noted that the Texas law discriminated upon viewpoint, i.e., although the law punished actions, such as flag burning, that might arouse anger in others, it specifically exempted from prosecution actions that were respectful of venerated objects, e.g., burning and burying a worn-out flag. The majority said that the government could not discriminate in this manner based solely upon viewpoint.
The Relative Clause is “who are five in number”. It is a type of dependant clause (it need the main clause in order to convey its meaning properly) that has the same function of an adjective; that is to say, it modifies a noun “friends”.