Two civil liberties groups in the US have taken legal action to block President George W Bush's domestic spying programme.
Mr Bush has said the eavesdropping will continue
The groups want an immediate halt to the "illegal and unconstitutional" eavesdropping on US citizens.
The federal lawsuits were filed in New York and Detroit by the Center for Constitutional Rights (CCR) and the American Civil Liberties Union (ACLU).
The president has defended the policy as critical to the war against terror.
Mr Bush signed a secret presidential order following the 11 September 2001 attacks, allowing the National Security Agency (NSA) to track the international telephone calls and e-mails of hundreds of people without referral to the courts.
Previously, surveillance on US soil was generally limited to foreign embassies.
The ACLU and CCR are seeking an injunction preventing the government carrying out electronic surveillance in the US without warrants.
Mr Bush and the head of the NSA, Keith Alexander, are named in the legal actions.
The head of ACLU, Anthony Romero, described the current monitoring of US citizens as "a chilling assertion of presidential power".
CCR legal director Bill Goodman said: "This illegal activity is cloaked in the guise of national security.
"In reality, it reflects an attempt by the Bush administration to exercise unchecked power without the inconvenient interference of the other co-equal branches of the government."
Other plaintiffs include Greenpeace, the Council on American-Islamic Relations and UK journalist Christopher Hitchens.
The New York Times, which leaked information about the spying policy last month, reported on Tuesday that much of the domestic spying was unproductive and led federal agents to dead ends or innocent US citizens.