The lawsuits accusing Mr. Bush of exceeding his constitutional powers were filed in federal courts were filed in New York by the Center for Constitutional Rights and in Detroit by the American Civil Liberties Union.
The New York suit – filed on behalf of the center and individuals – names Mr. Bush, the head of the National Security Agency, and the heads of the other major security agencies. It challenges the NSA's surveillance of persons within the United States without judicial approval or statutory authorization.
It asked a judge to stop the president and government agencies from conducting surveillance without a warrant of communications in the United States.
The Detroit suit, which also names the NSA, was filed by the ACLU, the Council on American-Islamic Relations, the environmental group Greenpeace and several individuals.
and in New York by the Center for Constitutional Rights (.pdf).
A White House spokesman called the lawsuits "frivolous" and said they will do nothing to enhance civil liberties or protect the American people, reports CBS News correspondent Mark Knoller.
"If you're not talking to a known al Qaeda member or a member of an affiliated organization, you don't have to worry about this," White House press secretary Scott McClellan said.
The plaintiffs find plenty to worry about, however, CBS News chief White House correspondent John Roberts reports. They are not suspected terrorists. They are attorneys and journalists who believe the government may have targeted their contacts with clients and sources overseas. While they have no proof, they argue the NSA is too powerful and needs to be checked.
Mr. Bush, who said the wiretapping is legal and necessary, has pointed to a congressional resolution passed after the attacks of Sept. 11, 2001, that authorized him to use force in the fight against terrorism as allowing him to order the domestic eavesdropping program.
Between the lawsuits and the pending Senate hearings, the White House is beefing up its defense. CBS News has learned the Justice Department is aggressively working to expand the legal justifications of the NSA spying program and could make those arguments in public later this week.
The program authorized eavesdropping of international phone calls and e-mails of people deemed a terror risk.
But the New York lawsuit noted that federal law already allows the president to conduct warrantless surveillance during the first 15 days of a war and allows court authorization for surveillance of agents of foreign powers or terrorist groups.
Instead of following the law, Mr. Bush "unilaterally and secretly authorized electronic surveillance without judicial approval or congressional authorization," the lawsuit said.
The Center for Constitutional Rights maintained its work was directly affected by the surveillance because its lawyers represent a potential class of hundreds of Muslim foreign nationals detained after the Sept. 11, 2001, terrorist attacks.
It said its attorney-client privilege was likely intercepted as it represented hundreds of men detained without charge as enemy combatants at the Guantanamo Bay Naval Station in Cuba and a Canadian citizen who was picked up at a New York airport while changing planes, sent to Syria and allegedly tortured and detained without charges for nearly a year.
The group said the surveillance program has inhibited its ability to represent clients vigorously, making it hard to communicate via telephone and e-mail with overseas clients, witnesses and others for fear the conversations would be overheard.
"The key battles in these cases are likely to come early when the government challenges the claims and then argues that the data that might prove what the plaintiffs have alleged cannot be disclosed due to national security concerns," says CBS News legal analyst Andrew Cohen. "So right off the bat we'll see a legal defense, not a factual one."
The lawsuit filed in U.S. District Court in Manhattan noted that rules on how the president can conduct surveillance were written before Congress enacted the Foreign Intelligence Surveillance Act of 1978.
The law was enacted after the disclosure of widespread spying on American citizens by various federal law enforcement and intelligence agencies.
The Detroit lawsuit said the plaintiffs, who frequently communicate by telephone and e-mail with people in the Middle East and Asia, have a "well-founded belief" that their communications are being intercepted by the government.
"By seriously compromising the free speech and privacy rights of the plaintiffs and others, the program violates the First and Fourth Amendments of the United States Constitution," the lawsuit states.