This reminds me when one norwegian was a victim of a cache error in the yearly release of tax information.
Everyone that logged in got his page until they shut it down.<p>Although this steam error is a bit different with everyone getting random users, it seems likely that it is along the same lines.
Over stressed servers maybe?<p><a href="http:&#x2F;&#x2F;www.tu.no&#x2F;it&#x2F;2012&#x2F;03&#x2F;23&#x2F;altinn-feilen-er-funnet" rel="nofollow">http:&#x2F;&#x2F;www.tu.no&#x2F;it&#x2F;2012&#x2F;03&#x2F;23&#x2F;altinn-feilen-er-funnet</a> (Norwegian)