The Careers 2.0 "My Profile" page allows you set "Public view" to "hidden" and "employer view" to "blocked" (in the detail/editing view the text is "Block all messages and searches")—does that really mean that my presence on stack overflow careers is "hidden" completely, or just that potential employers/searchers can't actually see the details of my profile?
The distinction I'm making is that in Facebook, for example, marketers can't see your actual profile, but it is possible to find people (and find out things about people) just by playing with the search settings until you have a small handful, and then by elimination deriving answers about that sample through further detailed searches—is this the same, or is having your profile blocked really information-leak-proof?
This is more of an idle curiosity question than one of practical importance, obviously (given that I'm here posting on meta about it, with my public profile :)).