Mr. Monsegur has been cooperating with the FBI since as far back as June and made possible arrests and charges against five of his top LulzSec deputies. In response, Anonymous hacked the website for Panda Security, a Spanish antivirus firm, and exposed passwords of dozens of members of the company's staff. The group also left a message for Sabu at the top of the defaced site.The message accuses Panda of helping law enforcement with the arrest of 25 Anons in Spain and South America last year. It also contains what Forbes calls a "bitter goodbye letter" to their former compatriot:

“Yeah yeah, we know, Sabu snitched on us. As usually happens FBI menaced him to take his sons away. We understand, but we were your family too. (Remember what you liked to say?),” the note reads, likely referencing Sabu’s habit of rallying his radical hacktivist “brothers” on Twitter. “It’s sad and we can’t imagine how it feels having to look at the mirror each morning and see there the guy who shopped their friends to police.”

And you thought cyber-terrorists didn't have any feelings!