Last night, there was a pretty significant security breach giving unauthorized access to your Google Webmaster Tools. Google has fixed the security issue this morning but not after it being an issue for probably about 12 hours.
@patrickaltoft pinged me about this last night on Twitter but I didn't see the issue myself in Google Webmaster Tools. Plus I didn't see any other complaints about it in the Google Webmaster forums. But State Of Search blog and David Naylor saw it and documented the issue. We later covered it at Search Engine Land after not hearing back from Google about the issue.
This morning, Google sent us a statement saying:
For several hours yesterday a small set of Webmaster Tools accounts were incorrectly re-verified for people who previously had access. We've reverted these accounts and are investigating ways to prevent this issue from recurring.
It is unclear if any damage was done over that 12 hour period but for some, it was incredibly nerve racking knowing that some people may have unauthorized access to your Webmaster Tools account and do some serious damage to your site in Google.
Here is a screen shot from David Naylor showing the unauthorized access:
This morning I spotted only a couple threads with complaints about the issue.
Did any damage happen to your site's due to this?