The Noerr-Pennington Doctrine

The Noerr-Pennington doctrine immunizes from antitrust liability legal persons (including individuals, but also corporations) who petition/lobby the federal or state government to take actions, such as pass legislation, that may impose restraints on trade.
 
Eastern R. Conf. v. Noerr Motors, 365 U.S. 127 (1961) http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=US&vol=365&invol=127 <http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=US&vol=365&invol=127>
 
United Mine Workers v. Pennington, 381 U.S. 657 (1965)http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=US&vol=381&invol=657
 
Noerr-Pennington Resource Page, ABA Antitrust Section, Exemption and Immunities Committee
http://www.abanet.org/antitrust/at-committees/at-exemc/main-exemptions/n...
 
Muris Speech Discussing Noerr (Looking Forward: The Federal Trade Commission and the Future Development of U.S. Competition Policy)
http://www.ftc.gov/speeches/muris/handler.shtm