Here are some anti-greifer ideas. Hope you like them!
Personal Space.
This one is pretty simple. you wouldn't be able to get to close to anyone. i'm sure you all had for experiences with too closeness to some... unpleasant people. same for NPCs, they shouldn't be able to get to close to each other. i mean during and invasion 5 skeletons can get by taking up the space of one, making it kind of unfair.
Spies.
Like club penguin, if any of you have played it or still do. i dont anymore, but what ever. so anyone with out ANY bans or warnings against you. you would have to be playing for a month or so. if you see anyone greifing or what not, you could press on them and ether press the "ban" button in witch they would get three warnings. first one, window pops up at the screen. second one window and not able to chat for 10 minutes. third, banned for a week. and what else you could do is make it so they can't chat for 30 minutes. anyone who gets one of these punishments would not be able to be a spy. a spy would only be able to punish 5 times a day. the only problem i see with this is that a spy might abuse there power. thats why i said they should only be able to punish 5 times a day. if anyone has any ideas on how to stop this, please post
Hope you like them!!!!!

please post what ever you think should be added and you option and what not!