A recent federal trial in Ohio offers new details about how the FBI uses informants in Muslim communities to gather intelligence on domestic terrorist threats.

Since Sept. 11, the bureau's aggressive use of such informants—including giving them the green light to spy on suspects inside mosques—has triggered concerns about potential civil liberties abuses. The issue  is threatening to become even hotter:  Attorney General Michael Mukasey recently confirmed he is expanding internal FBI guidelines governing the use of undercover informants in national security investigations. The proposed new guidelines, according to two senior law enforcement officials, would give FBI agents greater latitude to "task" undercover informants to collect intelligence in entire communities where potential threats are deemed to exist, rather than simply targeting specific individuals suspected of wrongdoing.

But a recent counter-terrorism case in Toledo, Ohio, shows how the FBI already started down that road in the wake of 9/11. Thanks largely to the work of a well-compensated FBI undercover informant, federal prosecutors last month secured the convictions of three Islamic radicals in Toledo on charges of conspiring to kill or maim U.S. troops overseas. FBI officials have touted the case as a major success story in part because it exposed what they see as an increasingly alarming phenomenon: the emergence of "homegrown" jihadis who cook up terror plots on their own after downloading violent extremist literature and terror training manuals over the Internet.

"O Mujahid brother, in order to join the great training camps, you don't have to travel to other lands," reads one of the manuals downloaded by the defendants from a Saudi Arabian website linked to Al Qaeda. "Alone in your home or with a group of your brothers, you too can begin to execute the training."

It is not clear how far the three Toledo men—all of Middle Eastern descent--would have gotten in their plans to attack U.S. troops in Iraq. Defense lawyers insist their clients were convicted based on mere "talk," not any actual acts of terrorism. But federal officials say the FBI would never have learned of the defendants in the first place had it not been for the work of a former U.S. Special Forces commando named Darren Griffin, who was recruited by the FBI after 9/11 and instructed to insinuate himself into the Toledo Muslim community, posing as a convert to Islam with extremist views.

"I'm profoundly disturbed that the government would send someone into the Islamic community to gather information without more specifics," said Steve Hartman, who represented one of the defendants, Marwan el-Hindi, a 45-year one-time travel agent and prison Imam. "The Islamic community should assume based on this that someone around them is working for the government. That's also disturbing."

Federal officials say that Griffin, who was paid more than $300,000 for his work, had previously served as an informant for the Drug Enforcement Administration. After the 9/11 attacks, the DEA suggested to the FBI that Griffin, who spoke Farsi and rudimentary Arabic and had been injured during a parachute jump overseas, could help the bureau in its new top priority mission of collecting intelligence on domestic Islamic extremists.