Last night, around 5pm, advertisers were unable to login to the Google AdWords console to manage their ads. The downtime reportedly lasted about an hour.
There were threads at Google AdWords Help and WebmasterWorld amongst others. The AdWords help had an official post from Google confirming the bug and when it went back online.
We're currently experiencing a technical issue with a part of our ad system. You may be unable to access your AdWords account to view your campaigns or make changes at this time. AdWords ad serving has not been affected, and your ads will continue to show as per your campaign settings. Please check this page for the latest updates.
For a short period of time, we experienced a technical issue that prevented AdWords advertisers from accessing their accounts. During this time, your ads continued to show according to your campaign settings. We've now resolved the issue, and you can once again log into your account to view your campaigns and make changes. We apologize for any inconvenience this issue may have caused.
AdWords users and support was active on phone support, online forums and Twitter responding to concerned advertisers.
Forum discussion at Google AdWords Help and WebmasterWorld.