AntiSec, a "hacktivism" partnership between Anonymous and former LulzSec members, released over 90,000 emails lifted from Booz Allen Hamilton's servers on Monday. The military contractor stayed quiet for most of the day, only to tweet vaguely in the late afternoon, "As part of @BoozAllen security policy, we generally do not comment on specific threats or actions taken against our systems."

They did not include word on whether they would be offering further response to one of the kind of novel part of the attack: Anonymous included an invoice for hacking the consulting firm:

 

The main Twitter account for Anonymous, @Anon_Central, had announced in the early morning hours, "Tomorrow will be the biggest day in #anonymous' history according to sabu. Get ready." This isn't the first time Sabu's used this kind of phrase when describing an Anonymous attack. In March, John Cook and Adrian Chen at Gawker identified Sabu as a leader of the allegedly leaderless collective and quotes him calling Anonymous's attack against HBGary--mentioned repeatedly in the Booz Hamilton release--the "greatest social hack of all time" in a private chat. Evidently the Booz Allen hack grew directly out of the HBGarry attack. The correlation is spelled out in the release:

HBGary Federal was just one of several companies involved in proposing software solutions for this project. Another company involved was Booz Allen Hamilton. Anonymous has been investigating them for some time, and has uncovered all sorts of other shady practices by the company, including potentially illegal surveillance systems, corruption between company and government officials, warrantless wiretapping, and several other questionable surveillance projects. All of this, of course, taking place behind closed doors, free from any public knowledge or scrutiny.