the only way to not being trolled passing his first turns and fucked up ur starting ?
few times i got a error msg in middle of a game : invalid joinkey ???? ohh nice another 100 rating lost

not sure if you can prevents people from trolling....
SOLUTION ???
1- u cant loose rating between 1st and the end of 3nd turns
2- any protection 1 space around your starting territory? or if someone start just beside you....his land start at 1 so he will loose 1 turns or the other will kill him....( people will stop to troll )