alt Hacker NewsWhat about sinking 3 2x4s into the ground and nailing a 4x8 sheet of plywood with a tastefully painted sign indicating the property is not for sale?
It won't stop everyone but any realtor doing due diligence will likely see it. If is lasts long enough, it will show up on Google street view as well.
A motivated attacker need only don a green safety vest and hard hat, then roll up with a white pickup truck, place some orange safety cones and take down the sign with a chainsaw.