The Electronic Privacy Information Center sued the FBI Wednesday, saying the agency should be forced to disclose information concerning its Carnivore email surveillance system.

The privacy advocacy group says the FBI should immediately release information on exactly how Carnivore is used. Carnivore was recently revealed to be a method used by the FBI to tap electronic mail communications during criminal investigations. The FBI has been reluctant to reveal Carnivore details, partly on the grounds that such exposure would let programmers create their own, malicious Carnivore clones. In an application for a temporary restraining order (available as a file download at EPIC's website), EPIC charges that the Department of Justice and the FBI failed to expedite the Freedom of Information Act request that it submitted to the agencies last month. EPIC officials contend this is illegal. The FBI says Carnivore is a "well-focused" system that has been used in only a small number of cases. The FBI maintains that while Carnivore is designed to specifically target individual email transmissions, the agency does not read the unrelated email that is caught in Carnivore's electronic net.