Sabu: Anonymous/LulzSec Hacker was FBI Informant
Hector Xavier Monsegur, aka Sabu, Snitched for FBI
Hector Xavier Monsegur, the Anonymous-linked hacker and de facto LulzSec leader known online as Sabu, was an FBI informant. Yes, the hacker who promoted #FuckFBIFridays was doing so from a desk at an FBI office.
Hector Xavier Monsegur (aka Sabu and Leon, according to court docs) was arrested in August 2011, and had been cooperating with the FBI ever since.
As more and more LulzSec- and Anonymous-affiliated hackers got busted, Sabu remained untouched. This led others to suspect that Sabu was providing info to the FBI. Turns out they were right.
Sabu was finally cornered at his Lower East Side apartment, and was trying to pass himself off as an actual FBI agent. Sabu was arrested for passing himself off as a federal agent. Snitches are not actual feds: they are useful up until the point where they are no longer deemed useful.
That time would be now. five Lulzsec hackers were arrested in an international swoop, based at least partly on information provided by Hector Xavier Monsegur. Additional charges were unveiled against Topiary and Kayla.
Below is the court case against Hector Xavier Monsegur.