Google Webmaster tools BREACH?
“A justified panic gripped the SEO industry after word got out that Google Webmaster Tools has an extremely serious technical issue – old user accounts are automatically getting re-verified and given access to sites they shouldn’t have access to anymore.” – SEJ
Basically the flaw or technical error allows old contractors or agencies to be added and verified as a new owner, all by this glitch, but it gets better. They are reporting they has access to Analytics reporting as well! This is just cause for someone to do something malicious to an ex employer.
Google has fixed the issue: “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.“