I need help, I've been on creative for a while now and, suddenly, a player comes onto my plot and starts writing threats. I have no idea who this guy is and do not want to lose all of my pixel art and such. This has happened two times now and I just want it to end. I'm not sure if there's anything you can do about it but, if there is, I'd like some help. Thanks.
Remove all helpers from your plot and the only thing you can do is disguise as an animal and keep looking at your plot.
Remove the players you do not trust by doing /plot remove <username>. You can figure out who is added by doing /plot info and looking under helpers. This will decrease your chances of getting griefed if you just keep the players you trust added and remove the ones you don't trust.