In a high-stakes game of Internet cat-and-mouse, the FBI is hunting an Israeli master hacker who orchestrated the penetration of military and university research computers.

Deputy Defense Secretary John Hamre said last month that although the intrusion appeared to have been aimed at systems that contained unclassified personnel and payroll records, it was "the most organized and systematic attack the Pentagon has seen to date."And computer experts noted that because information is shared within any organization, classified data could be available even on unclassified systems. And even unclassified data could be changed or erased.

The computer whiz, who uses the Internet name "Analyzer," boldly gave an interview with an online magazine.

And Analyzer supporters have threatened retaliation if the FBI cracks down on the hackers responsible for the electronic break-ins.

Those threats should be taken seriously, warns computer expert Dane Jasper, a partner in Sonic, a Santa Rosa Internet provider. He helped the FBI track down two Sonoma County teenagers who Analyzer allegedly coached through the series of military computer raids.

Most government and university computers are woefully unprotected, he says.

"If these systems are so important to the federal government, why isn't someone paying attention to patch the security?" he asks.

Analyzer and the two teens penetrated computers in February using a weakness that already had been identified by computer security teams. The teams provided a quick software patch - but the hacked systems didn't use it.

The first report came Feb. 3 from the Massachusetts Institute of Technology's plasma energy lab, followed by break-ins at a series of military locations, including the Naval Undersea Warfare Center. They were followed by reports from NASA and other universities.

One of the teenagers has claimed 200 institutions were hacked.