[arrogant]

This is exactly how okcupid's premium membership operates. You can always anonymously visit profiles, but unless you're a paid member, it'll no longer show you your visitors. Paying the premium lets you "stalk" others while still seeing who is visiting you.

[slig]

But on OkC, that's easily avoidable: just create another dummy account and stalk from there.

On FB, you can't just do that because people are now showing stuff to "friends only".