Unfortunately, it is ridiculously easy to hack someones account... Just run on an anonymous proxy and use a program to brute force the login page with a word list...
I have tried the system on my own personal website, and it's scary how effective it is... With a big enough user base you're sure to get some accounts after an hour or so of scanning.
Of course, I'm not stupid enough to do it on someone else's website (jail-time ftl), but I feel that the more you know about the tools hackers have available to them, the safer you are when trying to avoiding becoming a victim.