Valve sent the following statement to Kotaku: "Steam is back up and running without any known issues. As a result of a configuration change earlier today, a caching issue allowed some users to randomly see pages generated for other users for a period of less than an hour. This issue has since been resolved. We believe no unauthorized actions were allowed on accounts beyond the viewing of cached page information and no additional action is required by users."
Multiple Steam users got the bad kind of Christmas surprise today when what appears to be a caching error allowed them to access the information for other users, including partial credit card numbers and usernames.
Those going to Steam's website or using the client earlier today potentially found themselves with access to other accounts, some of which were in other languages. Information including purchasing history, email addresses, and PayPal info could be accessed, though the most important information remained censored. Mass confusion soon followed as users took to forums and social media. Over on the Steam subreddit, a moderator urged users to stop posting people's usernames and wallet sizes out of respect for their privacy.
On Steam's community website, a moderator released a basic FAQ assuring users that the service hadn't been hacked, and that credit card and contact info was censored as required by law. Valve has otherwise remained largely silent on the issue, but several sites have speculated that it stemmed from a caching problem.
In response to the glitches, Valve took Steam offline, but service has since been restored and the issue appears to have been resolved. We'll update you if there's any official word from Valve on this issue.
For now, even if no lasting damage was done, this glitch is yet another disconcerting reminder of how vulnerable personal information can be on online gaming platforms - an issue that continues to loom large long after the disastrous PlayStation Network attacks in 2011. And with gaming becoming more dependent on online access by the day, it's a concern that's only going to grow.