But SWIFT said in a statement that it has worked with U.S. officials to restrict the use of the data to terrorism investigations.
The program is part of the Bush administration's dramatic expansion of intelligence-gathering capabilities, which includes warrantless eavesdropping on the international phone calls of some U.S. residents. Critics complain that these efforts are not subject to independent governmental reviews designed to prevent abuse, and charge that they collide with privacy and consumer protection laws in the United States.
Steven Aftergood, director of the Project on Government Secrecy at the Federation of American Scientists, said the SWIFT program raises similar issues. "It boils down to a question of oversight, both internal and external. And in the current circumstances, it is hard to have confidence in the efficacy of their oversight," he said. "Their policy is, 'Trust us,' and that may not be good enough anymore."
A former senior Treasury official expressed concern that the SWIFT program allows access to vast quantities of sensitive data that could be abused without safeguards. The official, who said he did not have independent knowledge of the program, questioned what becomes of the data, some of it presumably related to innocent banking customers.
"How do you separate the wheat from the chaff?" the former official said. "And what do you do with the chaff?"
More than a dozen current and former U.S. officials discussed the program on condition of anonymity, citing its sensitive nature.
The effort runs counter to the expectations of privacy and security that are sacrosanct in the worldwide banking community. SWIFT promotes its services largely by touting the network's security, and most of its customers are unaware that the U.S. government has such extensive access to their private financial information.
U.S. officials, some of whom expressed surprise the program had not previously been revealed by critics, acknowledged it would be controversial in the financial community. "It is certainly not going to sit well in the world marketplace," said a former counterterrorism official. "It could very likely undermine the integrity of SWIFT."
Bush administration officials asked The Times not to publish information about the program, contending that disclosure could damage its effectiveness and that sufficient safeguards are in place to protect the public.