[rahoulb]

My guess is that the same machine is a big giveaway. There's a difference between leaving a trace of your presence on a shared computer accessed by many people and a computer accessed by one or two.

However, if people you know found the account, then that's also something that Facebook uses - I've had "do you know X?" suggestions from people with whom I have no traceable connections (not in my address book, don't even know their email addresses) - turns out (when I asked one of them) that he had been looking at my profile (without friend-requesting me) a few days before.