Brown v. Glines (1980) said military service members have the right to
petition Congress may not circulate petitions without approval from a base
commander.
California Motor Transport Co. v. Truckers Unlimited (1972) said the First
Amendment does not protect companies when they work together to prevent
others from access to courts.
McDonald v. Smith (1985) held that the petition clause of the First
Amendment does not endow individuals with absolute immunity from charges of
slander and libel.
Meyer v. Grant (1988) invalidated a provision of a Colorado statute that
made it a felony to pay people circulating petitions to include initiatives
on state ballots.
Secretary of the Navy v. Huff (1980) was decided in conjunction with
another case that said limiting the right of the military to petition does
not violate the First Amendment.