Piping up to absolutely agree with this suggestion.

I have had to lock my personal plot due to non-RPer neighbors who would crash into the house and squat / troll there constantly, and still treat the yard as their own. Had a similar problem with my FC house for a while, and still have occasionally found folks doing god-knows-what in the house until they're caught and hastily hearth. No trolls yet, but I would prefer not to deal with them should the issue arise.