Anonymous have mobilized. Well, a subset of Anonymous under the banner of Operation Payback have started attacking organizations that have discontinued services to WikiLeaks (at the time of writing there is no DNS name and it is located at 18.104.22.168). After reading several articles on the subject, I was familiar with the tool that Anonymous was using to attack these sites. From what I can tell there are several versions of the tool named Low Orbital Ion Cannon (or LOIC for short). LOIC is a modified version of an open source load tester. It was modified to connect to an IRC channel and get a list of targets to start attacking.