It seems that the upcoming release of Valve’s Portal 2 has inspired the corrupt computer GLaDOS to extend her corruption to the Portal 2 ARG (alternate reality game). This corruption is the start of the third phase of the ARG and has spurred a bevy of chaotic things to happen to the accounts and games of all of those involved. GLaDOS wants everyone to know that she is alive and, moreover, that you all broke her heart.
Details on the chaos that has been happening in the ARG can be found here. You can also follow the ARG on its wiki page which is located here. The Two Tribes games that are affected are Toki Tori and RUSH, but there are a number of other indie titles that have been affected by this craziness. Portal fans would do well to keep an eye out for any strange Easter eggs in their Steam games.