Due to political pressure and citing TOS violations, organizations from Paypal to Amazon Web Services began denying service to WikiLeaks. That's when things got interesting.  A loosely organized consortium of hackers Â that would be Anonymous Â who felt these anti-WikiLeaks actions were wrong decided to put some pressure on MasterCard et al. themselves by executing DDoS attacks on the websites of the offending institutions. Dubbing their initiative "Operation Payback," Anonymous has succeeded in taking down all or part of the websites of Visa, MasterCard, PayPal (which has since released funds to WikiLeaks) and Swiss bank PostFinance. The group even went after U.S. politicians who had made negative or even threatening remarks about WikiLeaks founder Julian Assange, including Sarah Palin and Sen. Joe Lieberman.  Anonymous also set up Facebook and Twitter accounts promoting awareness of their mission and links to tools to carry out the DDoSs.  The group's Facebook account was closed first; shortly thereafter, according to some reports, Anonymous began leaking what it claimed were MasterCard credit card numbers to its Twitter account. The Twitter account was shut down in short order, as well.  Since DDoS attacks aren't exactly legal, and a group organizing and promoting DDoS attacks on major financial and tech institutions isn't exactly legal, either, it's no surprise that Facebook and Twitter have swiftly shut the accounts down.  However, WikiLeaks's own Twitter and Facebook accounts remain operational.  Of course, Anonymous is expected to keep creating new accounts as quickly as Facebook and Twitter squash them; it's a bit like Whack-a-Mole or doing battle with a hydra, in that sense. Fighting Anonymous is a task we wouldn't wish on anyone.
Both Facebook and Twitter have closed accounts corresponding to Anonymous, a formerly 4chan-linked group organizing a string of DDoS attacks on organizations that refuse to work with WikiLeaks.We