A group who refers to itself as Anonymous has as taken credit for a recent string of high-profile cyber attacks against the websites of businesses, banks and politicians that have either spoken out against or stopped doing business with WikiLeaks. Cyber attacks, dubbed Operation Payback, targets those who have caved into US government pressure to shun the whistleblower website that recently released thousands of classified US diplomatic cables. The activist hackers have attacked MasterCard.com, PostFinance, Visa, Paypal.com, and others.