LulzSec on Tuesday, in a document posted on Pastebin, called the U.S. Federal Bureau of Investigation to put an eye on Marshal Webb, another hacker.

LulzSec said that Webb "was involved in the hacking of the game "Dues Ex" and was/is involved in countless other cybercrimes."
The group exposed the hacker for leaking chat logs belonging to LulzSec. LulzSec said that Webb is from Hamilton, Ohio, in the United States, and his associate, Michael, or "Hann" is from Halethorpe, Maryland. LulzSec gave out the two's home addresses, IP addresses, phone numbers and pictures. "These goons begged us for mercy after they apologized to us all night for leaking some of our affiliates' logs," LulzSec said.

The Lulz Security group is escalating its cyber attacks, now threatening to steal classified information from governments, banks and other high-ranking establishments.

On Wednesday the group's "Brazilian unit", attacked the Brazilian government's Web site. "TANGO DOWN brasil.gov.br & presidencia.gov.br LulzSecBrazil," LulzSec tweeted.

LulzSec in the past month has hacked Sony Corp., the U.S. Senate, an FBI affiliate, the Public Broadcasting System, gaming sites, and online porn sites. LulzSec's assaults, which it publicizes on the Twitter microblogging website, have mostly resulted in disruptions of some websites and the public release of user credentials.

LulzSec, however, said it is teaming up with the Anonymous hacker activist group to cause more serious trouble. "Government hacking is taking place right now, behind the scenes," LulzSec said on Monday in a message posted on Twitter, were it has earned more than 240,000 followers.

Following a joint effort by the U.S. Federal Bureau of Investigation and the United Kingdom's Scotland Yard, Ryan Cleary, a 19-year-old suspected major player of LulzSec, was arrested on Tuesday in Essex, England. Cleary is in custody at a central London police station and is being questioned on a suspicion of a Computer Misuse Act and Fraud Act offence.

Various reports indicate that Cleary is the mastermind of the group. LulzSec, however, tweeted, "Seems the glorious leader of LulzSec got arrested, it's all over now... wait... we're still here! Which poor bastard did they take down?"

"Ryan Cleary is not part of LulzSec; we house one of our many legitimate chatrooms on his IRC server, but that's it," the group added in a Twitter message. "Clearly the U.K. police are so desperate to catch us that they've gone and arrested someone who is, at best, mildly associated with us. Lame."

Cleary's half-brother Mitchell, 22, in an interview with United Kingdom-based The Sun said that Ryan used to be part of WikiLeaks, a splinter group of Anonymous, which last year launched digital assaults on MasterCard and PayPal. But Cleary's mum, Rita, 45, said she thought her son, who suffers from agoraphobia, was playing computer games in his bedroom and cannot believe he was hacking into security agency websites.