The first case, Red Lion Broadcasting v Federal Communications Commission, considers the constitutionality of a FCC rule requiring broadcasters to notify individuals who have been personally attacked in their programming, and to offer the attacked individual a chance to respond over the airwaves.  The Supreme Court unanimously upheld the FCC rule, concluding that scarcity of available spectrum space justified regulating broadcasting to ensure a diversity of voices.  The Court viewed broadcast licensees as trustees who take licenses with certain public interest obligations--obligations that may include complying with content-based regulations that could not be applied to other media.  (The scarcity rationale is later cited by the Court in FCC v Pacifica as a basis for upholding rules prohibiting "indecent" programming.)

It is interesting to contrast Red Lion with the Court's decision in Miami Herald v Tornillo, just five years later.  In Tornillo, the Court unanimously strikes down a Florida law that required newspapers to print the replies of individuals who had been personally attacked in newspaper editorials.  Despite the similarity of the question to that presented in Red Lion--and the fact that Red Lion was the case most discussed in briefs for both parties--the Court never even so much as mentioned Red Lion in a footnote!

In Reno v ACLU (1997), the Court considers what level of scrutiny should apply to content regulation of the Internet.  The Court decides the the medium deserves the highest level of First Amendment protection, noting that anyone and everyone can develop a website--the scarcity rationale of Red Lion for greater regulation therefore has no application.  Applying strict scrutiny, the Court proceeds to strike down as vague and unconstitutionally overbroad the Communications Decency Act of 1996.

American Amusement Machine Association v Kendrick (2001) is a Seventh Circuit case that produced an interesting opinion (by the always interesting) Judge Richard Posner.  Posner concludes for the Court that an Indianapolis ordinance prohibiting persons from making available to minors graphically violent video games violates the First Amendment.  Posner rejects the suggestion of Indianapolis that the interactive nature of video games makes them more potentially threatening and therefore justifies a greater degree of content regulation than could be applied, for example, to books or movies.