While these hackers are mentioned as leadership in the hacking group Anonymous, Sabu himself being referred to as the leader of LulzSec, Anonymous maintains what they have always claimed – that they are an ad-hoc, leaderless organization that will survive and remain at full strength. Taking to the twitterverse, @YourAnonNews and @AnonOps both had the following statement via tweet: #Anonymous is an idea, not a group. There is no leader, there is no head. It will survive, before, during, and after this time.
There's no telling how many more hackers or associates of LulzSec and Anonymous will be arrested thanks to Monsegur's help. As such Barrett Brown, more or less the public face for Anonymous, branded him a traitor for cooperating with Federal agents. In his words: "My apartment was raided this morning by the FBI. Feds also came to another residence where I actually was. Sabu is a traitor. #Anonymous." On a pseudo-related comedic note, Monsegur did get so deep into his role as an FBI informant that he tried to pass himself off as an FBI agent to police. On top of everything else, he picked up a second degree impersonation charge.
I don't believe for a second that this is going to be the end of Anonymous. Even if their claims of being a leaderless organization are false, and Sabu did in fact hold some sort of leadership role, the contacts Sabu turned over to the FBI will only get them so far. While the perpetrators of past crimes may end up behind bars, that's no guarantee that future perpetrators can be caught before something else goes off. Anonymous and other related hacking groups have a near-infinite pool of young bored technologists and disgruntled nerds with a great deal of skill. So far this looks like a black eye in return served by the Feds.