WASHINGTON (AP) - A secret Bush administration program to track people suspected of bankrolling terrorism drew protests from Democrats in Congress on Friday while Republicans defended the effort as vital to waging a global war against terrorism. Treasury Department officials acknowledged that in the weeks immediately after the Sept. 11 attacks they obtained access to an extensive international financial data base in order to track down the sources of terrorist financing. The information was obtained through use of subpoenas, which Stuart Levey, Treasury's undersecretary for terrorism and financial intelligence, called a "legal and proper use of our authorities." Treasury Secretary John Snow insisted that the effort was not "data mining or trolling through the private financial records of Americans. It is not a fishing expedition, but rather a sharp harpoon aimed at the heart of terrorist activity." Both Snow and Levey scheduled a news conference for later Friday to answer questions about the program, which was revealed on Thursday after several major newspapers rejected administration requests to keep it secret. Rep. Ed Markey, D-Mass. and co-chairman of the Congressional Privacy Caucus, said Friday that there were disturbing similarities between the bank monitoring program and the secret surveillance program for telephone calls that was revealed last year. "Like the domestic surveillance program exposed last December, the Bush administration's efforts to tap into the financial records of thousands of Americans appear to rely on justifications concocted without regard to current law," Markey said in a statement. "If the administration wants to fight terrorism legally, then it should ask for the authority it needs and then follow the law that Congress passes," Markey said. "Don't claim 'temporary emergency' and then operate in secret for five years." However, Republicans defended the effort. Amy Call, a spokeswoman for Senate Republican leader Bill Frist, said Friday that he had been briefed on the program and had "full confidence in the effectiveness of, and the legal authority for, this vital anti-terrorism tool." Dana Perino, deputy White House press secretary, said that "one of the most important tools in the fight against terror is our ability to choke off funds for the terrorists." Under the program, U.S. counterterrorism analysts could query an international data base known as Swift to look for information on activities by suspected terrorists as part of specific terrorism investigations, a Treasury Department official said. They would do so by plugging in a name or names, the official said. The program involved both the CIA and the Treasury Department. Swift, or the Society for Worldwide Interbank Financial Telecommunication, is a cooperative based in Belgium that handles financial message traffic from 7,800 financial institutions in more than 200 countries. The service, which routes more than 11 million messages each day, mostly captures information on wire transfers and other methods of moving money in and out of the United States. It doesn't execute these money transfers. The service generally doesn't detect private, individual transactions in the United States, such as withdrawals from an ATM or bank deposits. It is aimed mostly at international transfers. In a statement, Swift said it had negotiated with the U.S. Treasury "over the scope and oversight of the subpoenas." "Through this process, Swift received significant protections and assurances as to the purpose, confidentiality, oversight and control of the limited sets of data produced under the subpoenas," the service said. "Independent audit controls provide additional assurance that these protections are fully complied with." The administration defended use of the program, saying it plays a vital role in its efforts to identify terrorist financiers. "Our subpoena of terrorist-related records from Swift has provided us with a unique and powerful window into the operations of terrorist networks," Levey said. The existence of the program was first reported Thursday night on the Web sites of The New York Times, the Los Angeles Times and The Wall Street Journal. While confirming the newspaper reports, both Levey and Perino expressed concern that disclosure of the program could undermine efforts to track terrorism-related activities. "We know the terrorists pay attention to our strategy to fight them, and now have another piece of the puzzle of how we are fighting them," Perino said. The decision to publish was "a tough call; it was not a decision made lightly," said Doyle McManus, the Los Angeles Times' Washington bureau chief. Treasury Department officials spent 90 minutes Thursday meeting with the newspaper's reporters, stressing the legality of the program and urging the paper to not publish a story on the program, McManus said in a telephone interview. Disclosure of the program follows intense controversy over President Bush's directive ordering the National Security Agency to monitor -- without court approval -- the calls and e-mails of Americans when one party is overseas and terrorism is suspected. That program, which also began shortly after 9/11, was disclosed by The New York Times. The New York Times and Los Angeles Times quoted their editors as defending their decision to publish the financial data tracking effort despite being asked by the Bush administration to withhold publication. Bill Keller, The New York Times' executive editor, said it considered the administration's arguments but in the end decided to publish. "We remain convinced that the administration's extraordinary access to this vast repository of international financial data, however carefully targeted use it may be, is a matter of public interest." Dean Baquet, editor of the Los Angeles Times, said: "We weighed the government's arguments carefully, but in the end we determined that it was in the public interest to publish information about the extraordinary reach of this program." Yup, and we are assured that assurances have been given.