The term “bivens actions” is generated from Bivens v. Six Unknown Named Agents 456 F.2d 1339 (1972), in which the Supreme Court held that a violation of one’s Fourth Amendment rights by federal officers can give rise to a federal cause of action for damages for unlawful searches and seizures. Now, bivens actions generally refer to actions for damages when there has been a violation of the U.S. Constitution by federal officers acting in the color of federal authority. The plaintiff in a bivens action must demonstrate that a constitutionally protected right has been violated by the federal officers.
There are some exceptions to bivens actions. Nixon v. Fitzgerald 457 U.S. 731 (1982) held that the President of United States is entitled absolute immunity from bivens actions. Butz v. Economou 438 U.S. 478 (1978) found that officers engaged in adjudicatory functions are entitled to absolute immunity from damages for their judicial acts.
Bivens v. Six Unknown Named Agents 456 F.2d 1339 (1972) : http://www.law.cornell.edu/supremecourt/text/403/388