Congress is expected to approve Wednesday a White House-backed bill to update the Foreign Intelligence Surveillance Act -- the most sweeping change in the 30-year-old law and one that may further expand the use of evidence gathered by intelligence agencies in criminal cases.
FISA determines how the government conducts intelligence surveillance. Before Sept. 11, 2001, intelligence agencies could not readily share information with federal prosecutors. After the terrorist attacks in the U.S., those rules were relaxed. The Justice Department says that since 2001, there has been a fourfold increase in the number of requests by prosecutors to use information derived from eavesdropping. The great majority of requests are approved.
The new legislation offers a window on how prosecutors have been using such surveillance, and it has spurred a sharp debate over the bill's likely impact on civil liberties.
FISA dates to 1978, when post-Watergate sentiment favored curbs on presidential power. The Bush administration, initially distrustful of the law, now argues in favor of the new bill, in part because it would give conditional retroactive legal immunity to telecommunications companies that allegedly aided the administration's surveillance program, which operated outside FISA's limits.
While much debate has centered on telecom immunity, arguably of greater importance are changes to the law that would let the government seek more-sweeping surveillance orders, easing the work of intelligence officers who previously had to seek specific warrants for communications involving individuals in the U.S.
Bruce Fein, an associate deputy attorney general in the Justice Department during the Reagan administration, is among those who distrust the government's motives for revising FISA. "There's nothing to show that lowering the [civil liberties] standard improves intelligence," he said.
Justice Department officials dispute that prosecutors are abusing the law. They say that the increasing role of such information in national security cases helps explain the increase in the use of FISA-related material in prosecutions and that despite the fourfold increase, the number of such requests, which is classified, remains small.
"The vast majority of activities authorized under FISA are used only for intelligence purposes and not for criminal cases," said Matthew G. Olsen, deputy assistant attorney general and chief of the Justice Department's Office of Intelligence.
Among the dozens of cases in which information obtained through FISA has surfaced is a case against Rahmat Abdhir, a California computer engineer. Mr. Abdhir faces federal charges of providing material support to his brother, who is designated by U.S. national-security officials as a senior member of a group blamed for terror attacks in the Philippines.
One FISA intercept prosecutors cited in court filings is an email from Mr. Abdhir's brother Zulkifli Abdhir, who was indicted but remains at large. Corresponding with Rahmat Abdhir from a jungle hideout after a battle against U.S.-backed Philippine soldiers, according to the intercepted email introduced in court, Zulkifli Abdhir wrote on Feb. 6, 2007: "Over here the price of a M60 machinegun is 6000 USD..." According to an email prosecutors said was intercepted with a FISA warrant, Rahmat Abdhir replied: "God willing...I will make a deposit when I have more money later."
An attorney for Mr. Abdhir declined to comment.
The case of Brandon Mayfield offers a different picture of the expanded powers the government enjoys under FISA since the 9/11 attacks. Mr. Mayfield was mistakenly jailed for weeks by federal agents after a series of investigative errors landed him on a list of possible associates of the terrorists who carried out the 2004 Madrid train bombings. Weeks later, the government released him and eventually apologized for the mistake.
Mr. Mayfield sued, and as a result of his case, a court declared unconstitutional portions of the Patriot Act, one of several laws passed after 9/11 that loosened restrictions on FISA use. Other courts have made different rulings. The Justice Department is appealing the Mayfield ruling and says the errors in the case were not related to FISA.
Some critics say an expanded FISA, whose rules are more permissive than those that control domestic wiretaps, gives prosecutors an unfair advantage. FISA surveillance warrants, which are handled in secret by an intelligence court, are different in several ways from wiretaps issued under so-called Title 3 orders. For example, targets of Title 3 wiretaps eventually are notified that they were under surveillance, and defense attorneys can seek more information underlying the cause for the wiretap.
Some suspect prosecutors are using FISA to get information they otherwise would have problems getting because of Fourth Amendment search-and-seizure protections. "Prosecutors are using FISA as an end run around the Fourth Amendment," said Jameel Jaffer, counsel for the American Civil Liberties Union.
"Federal courts across the country have consistently found FISA to be constitutional in criminal cases," Mr. Olsen said. "And given the sensitivities of intelligence investigations and methods, we use FISA information sparingly in criminal cases."