Hi guys!
A person from this forum with good reputation stole 52000$ (now it is 11,02 BTC). I send it in october. What I need to do? Please help!

Do you know the username of the person? If so create a thread in the scam accusation (if you were scammed) or the reputation boards in this forum. This won't help you get your BTC back it will help others avoid dealing with that person.
Scam Accusation Board:
https://bitcointalk.org/index.php?board=83.0Reputation Board:
https://bitcointalk.org/index.php?board=129.0I'd also consider leaving the person negative trust equivalent to the amount of Bitcoin you lost.