If you log in to you 50BTC.com account you're in for a pleasant surprise, unfortunately it is one that wont last.
It seems that someone has gained access to 50BTC's servers and managed to increase all of our balances, the website recently put up a message saying;-
Our billing server have been hacked, some parameters currently shown incorrectly. At this moment we are working hard to restore actual user balances. Please be patient it can take up to 24 hours.
In the below screenshot the MinePeon backup account has accrued a total of 659.66862212 BTC or \$117,722.29 USD at today's rates.
I have not tried to withdraw my new-found balance, and I suspect that it wont work.