Because direct-mail solicitations in the wake of accidents are perceived by the public as intrusive, the Bar argues, the reputation of the legal profession in the eyes of Floridians has suffered commensurately. … We have little trouble crediting the Bar's interest as substantial.

But we have never held that the government itself can shut off the flow of mailings to protect those recipients who might potentially be offended. The First Amendment does not permit the government to prohibit speech as intrusive unless the “captive” audience cannot avoid objectionable speech. Recipients of objectionable mailings, however, may effectively avoid further bombardment of their sensibilities simply by averting their eyes. Consequently, the “short, though regular, journey from mail box to trash can … is an acceptable burden, at least so far as the Constitution is concerned.”