Give a store your e-mail address, it’ll find you on Facebook

Facebook wrote up a post on Sunday attempting to explain some of its new approaches to selling and analyzing ads on the site, responding to user alarm about its partnership with data firm Datalogix. Among the revelations: stores can give Facebook hashed versions of customer e-mail addresses they’ve collected to target users with ads, and Facebook is allowing users to opt out of entire ad networks via a link in real-time ads.