Currently, there are too many people who delight in ruin the game for other players. I find it pathetic. It starts with insults, continues with slander, goes on with trolling and finally the beautiful grief (either obviously a large area or only individual tiles)
It is currently not possible to operate a public server. Registration solves the problems not really. Reduces only frequency. I had already griefers on my servers with registration. The behave properly for 1-2 days ... next day I went online and everything was destroyed. As a server operator I don't want to waste another hour again every day, just to pick out save without the grief. -> Simply lacks the ability to undo a player's change.
If not all was destroyed, users 'll diligently build further. -> That they aren't happy when I load an older save file, should be clear.
The hash system brings as little as an ip ban. (based on public servers). Both can be regenerated with a few clicks.