Valve took down the Steam forum this morning temporarily to do some maintenance work. However, reports from various quarters are saying that the reason behind this is that Steam had been hacked. These reports and comments are mostly coming from individuals who were on the Steam forum website before it went offline.
Right before going offline, users saw a new category in the forum that directed them to open a site named "Fkn0wned." Many users also complained that their email ids related to Steam accounts were "spammed with ads for the web site," as reportedby The Inquisitr.
The group, Fkn0wned, over allegations of hacking of Steam forum, took down the web site and also claimed that they are not responsible for the situation.
No official comment has been made yet by Valve and it has been presumed that no personal data was exploited. However, it is advisable that users change their password to avoid any untoward events.
In case hacking theory is true, the cause can be attributed to vBulletin software which Valve blamed in the past.