[justcommenting]

It's more likely to be associated with built-in malware protection/phishing protection from Google. In Firefox's settings under Security, you can un-check "block reported attack sites" and "block reported web forgeries" and these cookies should disappear after running BleachBit.

these types of cookies may seem benign and helpful to users (and maybe they are), but i also wouldn't doubt that Google uses this information for persistent tracking.

it's already been disclosed that NSA uses Google PREF cookies to track users: http://www.washingtonpost.com/blogs/the-switch/wp/2013/12/10...

hence my other dispirited comment about the cookie UI... edit: reworded/clarified

[xenophonf]

At first I was only concerned about web page access tracking via this cookie (which indeed is set because of Safe Browsing---I turned both settings off, cleared my history, and the cookie is gone). If this cookie could be abused for location tracking, maybe it would be a good idea to leave Safe Browsing disabled.