The American Civil Liberties Union last week complained to the House of Representative's Judiciary Subcommittee that the system--which is installed on the network of an Internet service provider and monitors all mail and records coming to or from a suspected criminal--"raises new legal issues that cry out for Congressional attention." The subcommittee says it will hold a hearing on July 24 to "look at the balance between law enforcement needs and constitutional privacy rights, and examine the extent to which current statutes let the federal government use devices such as Carnivore to gather electronic communications."

One ISP already has filed--and lost--an appeal to keep Carnivore out of its system. While declining to name the ISP involved in the case, the company's attorney, Bob Corn-Revere of Washington law firm Hogan & Hartson, says he finds it "remarkable that the magistrate upheld the order to install the device."

ACLU associate director Barry Steinhardt says Carnivore gives the FBI "the ability to capture an ISP's whole traffic load" and that E-mail searches must be more clearly restricted. But FBI spokesman Paul Bresson says the brouhaha stems from a lack of understanding of the technology, which is designed to "fine-tune the information we can extract to what's contained in a court order."

So what's an ISP to do if the FBI comes knocking at its door with Carnivore? "You can refuse to obey the order and go to court. The ACLU stands willing and able to assist you," Steinhardt says.