"An apparent security glitch in Google's software for webmasters has resulted in former contractors for big Web sites being granted access to those sites once again."
This might be old news now, and Google have said:
Update, Wednesday 1:30 p.m.: A Google spokesman sent this statement: "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." Also, contrary to some reports, Google analytics was not affected by the glitch.
BUT, today I logged into Webmaster Tools and have access to a site I no longer work on and didn't have access to previously. Luckily I'm not nasty and am on good terms with the site-owner - but imagine the damage I could do.
The owner of another site I used to work on got an email saying:
A new user has been verified as an owner of hiswebsite.com: myemailaddress.com
(although I can't see that one when I log in to WMT).
This is a serious security glitch that you'd have thought would have been sealed up pretty quickly.