An anonymous reader writes "The Guardian reports that the FBI and CIA have 'persuaded' up to 25% of US hackers to 'work' for them. 'In some cases, popular illegal forums used by cyber criminals as marketplaces for stolen identities and credit card numbers have been run by hacker turncoats acting as FBI moles. In others, undercover FBI agents posing as "carders" – hackers specialising in ID theft – have themselves taken over the management of crime forums, using the intelligence gathered to put dozens of people behind bars. ... The best-known example of the phenomenon is Adrian Lamo, a convicted hacker who turned informant on Bradley Manning, who is suspected of passing secret documents to WikiLeaks.' What implications does this hold for privacy? Or is it just good work by the authorities?"
As you may have guessed, the estimate appears to be based only on the number of black hats, rather than all hackers.