The U.S. Supreme Court on Tuesday refused to hear a privacy invasion suit against the country\'s telecommunications carriers for secretly helping the National Security Agency (NSA) monitor phone calls and emails from and into the United States. In a one-line order, the court said it would not hear the case of Hepting v. AT&T, turning down appeals from civil liberty activists contesting the mass wiretapping, which was granted retroactive immunity in 2008 by Congress. The decision effectively ended the 6-year class-action suit. Lawyers for the Electronic Frontier Foundation and the American Civil Liberties Union appealed to the Supreme Court, arguing that the retroactive immunity was an \"unprecedented violation of the separation of powers\" because it allowed the executive branch to shield itself from accountability. The suit was triggered when Mark Klein, a retired AT&T engineer, revealed the company had allowed the NSA to tap into its switching devices, conducting allegedly unconstitutional surveillance of all the data crossing the Internet. After dozens of lawsuits were filed against the telecommunications carriers, the U.S. Congress passed a measure to shield them. It said a civil suit against \"any person for providing assistance to an element of the intelligence community shall be promptly dismissed\" if the U.S. attorney-general invokes this provision in a court case.