At a Girl.
Listen up, if you're thinking about creeping up on some unsuspecting girl I've got some advice for you: Don't do it. The best way to deal with a woman is to talk to her directly. If you like the girl in a store you frequent, introduce yourself to her and ask her out. Don't stalk her online; don't stalk her in real life.
Moral of the Story: Don't be a fucking creep.