Izz ad-Din al-Qassam Cyber Fighters compromised the sites of CitiBank and Bank of America via distributed denial-of-service (DDOS) attacks twice yesterday. Reportedly Bank of America has been targeted by this group previously however this is the first time these hackers compromised Citi servers.
Source: http://hilf-ol-fozoul.blogspot.ro/2012/12/citibank-next-target-for-al-qassam.html