Is there any legal background against bit coin cheaters,who using scam sites for cheats people..
This may be possible in other parts of the world but my country is an exception. Government made it known that anyone involved in bitcoin is doing so at his/her own risk. But I think if you have clear evidence you may be supported by the high courts of justice.
At this time it is not possible because the governments have nothing to do with bitcoin and you cannot claim your lost bitcoin. For many countries bitcoin is illegal and governments do not allow trading in bitcoin. All the people buy and sell bitcoin without the permission of their governments. May be in the future we can take legal actions against cheaters.