The famous LulzSec group has been disbanded after they announced it officially in PasteBin and also in Twitter. They also released a link to a torrent file hosted at ThePirateBay that includes lots of usernames and passwords and also other private data that they gathered during the last fifty days of their operation.
So far, they have attacked Sony, NATO E-Bookshop, Nintendo, Fox, and many other government agencies, including CIA and US Senate, Arizona police and the UK's Serious Organised Crimes Agency (SOCA).
Although they disbanded the group, it doesn't mean that other attacks will stop. Everyone should be aware of other attack in the future. Don't loose your security perimeter. You should tighten your system to prevent attacker crack into your system.