Operation Avenge Assange
"In December 2010, the document archive website WikiLeaks (used by whistleblowers) came under intense pressure to stop publishing secret United States diplomatic cables. In response, Anonymous announced its support for WikiLeaks, and Operation Payback changed its focus to support WikiLeaks and launched DDoS attacks against Amazon, PayPal, MasterCard, Visa and the Swiss bank PostFinance, in retaliation for perceived anti-WikiLeaks behavior. This second front in the December offensive was performed under the codename Operation Avenge Assange. Due to the attacks, both MasterCard and Visa's websites were brought down on December 8. A threat researcher at PandaLabs said Anonymous also launched an attack which brought down the Swedish prosecutor's website when WikiLeaks founder Julian Assange was arrested in London and refused bail in relation to extradition to Sweden."