Most people being hacked use weak login/pass/ID/secret answer or even backdoored hacks.
Some other use the same info as for other games or forums, msn, email etc.
I have been playing games which need a l/p for a few years, and I have never been hacked.
I always use login data with random characters, eg. "Sml10sl1/s92vA01" which gives no chance to brute forcers. (except the hashing algorithm is very weak.)
The people saying they can hack your account are braggers, unless they do not prove it on an account you made with secure infos, don't believe them.
If anyone here or your friends think they can hack an account, I will make a new account and show you that they are nothing but braggers.