11 April: 17 year old from New York wrote a worm that exploits an XSS vulnerability on Twitter and brought Twitter on it's knees. Sure the worm was mostly harmless, meaning no sensitive information was stolen by the author. Story on xssed.com (including worm code).
16 April: Apparently some hackers didn't like the publicity the worm author has received and hacked into his own system, posting personal and sensitive information (as passwords) here .
On January 2009 a hacker brute forced the site and managed to find an admin password, and thus was able to hijack multiple high profile accounts - more.