October 2011 – Bitcoin7 Hack

bitcoin7.com

Bitcoin7 was a business operating in 2011 that was once the third-largest BTC/USD exchange behind Tradehill and Mt Gox. On October 5, 2011, the company reported a theft of 5,000 BTC allegedly stemming from a group of Russian hackers. However, many believe the breach was an inside job and employees ran off with the funds. The Bitcoin7 domain was later sold for $10,000 USD in 2013, but has been offline ever since this incident.

Founder: http://tinypic.com/view.php?pic=25irtz4&s=8#.XTC5cZMzaqA

Website: http://web.archive.org/web/20111026145535/http://bitcoin7.com/

mybitcoins

June 2011 – MyBitcoins Hack

bitcoinica

March 2012 – Bitcoinica Hack