From the Center for Constitutional Rights' website:

On August 9, 2007, the Center for Constitutional Rights (CCR) appeared before Federal District Judge Vaughn R. Walker to argue that the NSA's program of warrantless surveillance is unconstitutional and should be struck down. The argument in CCR v. Bush comes days after Congress and the Bush administration passed the Protect America Act of 2007 which broadly expands the government's power to spy on Americans without getting court approval.

According to attorneys, there are substantial questions about whether the new law, which is temporary and due to expire in six months, is constitutional, and they will seek permission to file additional legal papers to that effect today. The law effectively removes oversight for spying from the FISA court and leaves it up to the Executive Branch to monitor itself, with Attorney General Gonzales having the primary responsibility for oversight. For that reason, CCR attorneys will argue in court today that the new law violates the Fourth Amendment's requirement that judges approve warrants for surveillance and do so only on evidence of probable cause.