From reddit: I used to hack accounts from a major social website when I was a tween.
"I won't give away too much information. There was a subculture on that site of hacking other users' accounts that had some kind of special value to us (very short usernames, huge popularity...). I started out clueless and learned as I hung with the more knowledgeable people. There were a variety of methods that anyone could use to hack some account..."