Yep. Not a lot I can do about that, given the nature of it. Be nice if there was an "add only" mode. I'll try and keep an eye on it though. On the plus side, being open, if anyone does screw it up, anyone can fix it too (if what they did is obvious).
is there a way to back it up? cause if so then you could design a program that backs it up every few days, and saved it somehow, then if someone reports it changed, then they could just get the program's data and put it back. it could save the past few backups incase it goes unnoticed for a while
People editing the map is already starting to piss me off. I've had to put the description text back 4 times already, and somebody deleted my marker. :|