Telephone companies and civil liberties groups are going to federal court to fight attempts by the Clinton administration to extend police wiretap authority into the world of mobile phones and computer networks.

Wiretapping has become one of the thorniest issues of the administration as law enforcement officials struggle to cope with the fast-changing technologies of the telecommunications industry.

At the urging of the FBI, in 1994 Congress passed the Communications Assistance for Law Enforcement Act, requiring telecommunications companies to design wiretap capabilities into their new networks. At the time, FBI Director Louis J. Freeh testified that the law was "intended to preserve the status quo" in the endless battle between good guys and bad guys.

Since then, however, the telephone companies have protested that the FBI wants more information than it ever got from traditional wiretaps. The FBI, for example, has demanded that the companies allow law enforcement agents with proper warrants to track the location of mobile phone callers and that agents be able to continue to monitor conference calls after the person directly under surveillance hangs up.

The dispute ended up at the Federal Communications Commission this summer, and the FCC sided largely with the FBI. With a deadline for protesting the FCC action in federal court coming up next Monday, the filings have begun to appear.

The U.S. Telecom Association filed a petition in the U.S. Court of Appeals for the District of Columbia on Nov. 9 asking for a quick review of the FCC ruling, saying that the FCC "broadly expanded the electronic surveillance capabilities that telecommunications carriers must provide" and ignored the heavy costs of compliance for the companies.

The American Civil Liberties Union and two online policy groups, the Electronic Privacy Information Center (EPIC) and the Electronic Frontier Foundation, said they will file a petition today.

A draft of that filing provided to The Washington Post calls the FCC ruling "arbitrary, capricious, an abuse of discretion and otherwise contrary to law" that "conflicts with privacy interests protected by both the constitution and federal statutes."

Two other groups, the Cellular Telecommunications Industry Association and the Center for Democracy and Technology, are expected to file their own cases by the Monday deadline for challenging the FCC rule. The civil liberties groups contend that the FCC's interpretation of the law tips the delicate balance struck in the Fourth Amendment of the constitution between the search and surveillance needs of law enforcement and the privacy rights of citizens.

"This is a fundamental privacy issue for the public," said David Sobel of EPIC.

"We all want law enforcement to be able to do what law enforcement does best, which is to capture criminals," said Kurt Wimmer, a Washington lawyer working with the ACLU and EPIC. But Wimmer said "the constitution has to apply with full force in the digital world" as it does in the world of copper wires.

The FBI did not return calls seeking comment.

FCC spokeswoman Joy Howell said that the ruling does not extend the FBI's powers. "These tools give law enforcement officials the same capability in the wireless world that they have in the wired world," Howell said. "Our order carefully balanced the interests of all these players and upon review we feel confident that the court will agree."