The FBI and Secret Service have successfully infiltrated the underground world of computer hackers in the US: 25 percent are secretly informing the government about their peers for fear of a long prison sentence. In fact, the community is riddled with paranoia and mistrust as it is not clear who is part of this "army of informants."

The estimate comes from Eric Corley, who publishes the hacker quarterly 2600. "Owing to the harsh penalties involved and the relative inexperience with the law that many hackers have, they are rather susceptible to intimidation," Corley told the Guardian.

Even popular illegal forums used by cyber criminals as marketplaces for stolen identities and credit card numbers are sometimes run by hacker turncoats acting as FBI moles. It's not just hackers though: undercover FBI agents sometimes pose as hackers specializing in ID theft and take over the management of crime forums so they can gather intelligence and put criminals behind bars.

This is one of the US government's strategy in fighting the anarchistic co-operatives known as "hacktivists" that have launched several high-profile cyber-attacks in recent months designed to make a statement. Two of the most popular groups that have been all over the news are Anonymous and LulzSec.

Last month, the US disclosed its International Strategy for Cyberspace. The document revealed the US government could respond to cyber-attacks with military force, especially if someone were to pull off a serious cyberspace hack against the US, its allies, its partners, or in a way to threaten its interests.

Informants are one thing, but I'm wondering how many of these hackers have been recruited by the FBI or the Secret Service. That's a statistic we'll probably never know.