Half-Life 2 source leak
For more details on this topic, see Half-Life 2#Source code leak.
In early September 2003, an unpatched security flaw in Microsoft Office XP (2002) was used to obtain the Half-Life 2 source code.[6] After it was first released on the myg0t website,[7] Valve CEO Gabe Newell publicly explained the events, and requested users to track down the perpetrators if possible.[8] After hearing this, "Sirus", a former myg0t member, decided to attempt to help. He scammed the key to the myg0t Internet Relay Chat channel and was able to listen in on the incriminating discussions about the leak. Before long, Newell received an email from a gamer under the name "Da Guy", confessing to the leak.[7]
http://en.wikipedia.org/wiki/Myg0t