The Steam forums were apparently hacked last night.
Multiple users have reported getting redirects to a hacking website when visiting the forums, which are currently down for maintenance.
According to Kotaku, the redirects were to Fkn0wned.com, offering "hacking tutorials and tools, porn, free giveaways and much more".
Some users also claim to have received email spam from Fkn0wned.com following the hack, although the site itself denies responsibility for any breach.
It said on its site: "Fkn0wned Forum is currently unavailable In lights of someone crediting us for the recent breaches of steam forums, the board is offline. Fkn0wned is not responsible."
The report points out that Steam User's Forums and Steam service account passwords are separate.
A message on Steam reads: "The Steam Forums are temporarily offline for maintenance. Your patience is appreciated."