A public interest law firm is a private association of attorneys whose principal goal is to assist clients in a particular area of law and advance certain ideological goals rather than to make money. The primary goal of private law firms is to make money practicing law. Public interest law firms usually have a different agenda. There are many public interest law firms that defend civil liberties, advance guns-rights and libertarian points of view, advocate on behalf of religious causes, and defend certain types of cases. Some well known public interest law firms include: National Legal Aid and Defenders Association, Alliance Defense Fund, Legal Services Corporation, American Civil Liberties Union, National Center on Poverty Law, Public Justice, the Rutherford Institute, and the American Center for Law and Justice.