Perhaps the most potent law that permits private citizens to prosecute criminal conduct is the Federal False Claims Act. The law, originally referred to as the "Lincoln Law," was enacted in 1863 in the wake of the Civil War to combat the problem of fraudulent defense contracts. Congress amended the law substantially in 1986, and the Act now permits private plaintiffs to file civil "qui tam" actions on behalf of the government against contractors and other parties who knowingly defraud claims for payment. These "qui tam" suits are purely civil actions and do not threaten defendants with criminal sanctions. A second area in which private plaintiffs can bring actions to enforce public obligations is Federal environmental law. The Clean Air Act, Clean Water Act, Endangered Species Act, Toxic Substances Control Act, and several other Federal statutes permit "any person" to bring a civil suit against parties who violate the substantive provisions of those laws. These laws thus eliminate the normal standing requirements for private plaintiffs. California's Unfair Competition Act is unique among similar State laws in authorizing "any person" to serve as a private attorney general to enforce the statute "for the interests of itself, its members or the general public." The Act's substantive provisions embrace a broad range of consumer protection and honest business requirements. Perhaps the greatest drawback of private actions to enforce the law is that these suits are limited to claims for monetary sanctions and injunctive relief; they do not threaten defendants with criminal punishment. Private prosecution still offers enormous potential benefits by bringing violations to public attention, thus making criminal prosecution possible. The particular justifications for private prosecution of environmental and white-collar crimes do not, however, apply with equal force to most ordinary criminal laws. 53 references