You're right but there's one useful thing called SocialEngineering =)

that is only a f****** small and simple example that also one of the greatest sites can be vulnerable.

I want to say ... safety doesn't exist .

Fugitif, you are damn right! And what goes for the Social Engineering part, imho, I think it isn't a pure 100% hack, because you get your victim to tell you a lot about her. I don't argue, you must have a strong logic, but I am more fond of the technical side of hacking. But, hey, that's just me =)