The kicker there is also scrawled on the side of the old washer is a lil stick figure that says 'you' with the bullet holes from the owner applied.... ????ÿ
I've seen this sign:
"Anyone found on this property at night, will still be here in the morning".
Back on the old forum, someone came up with a hypothesis that the more expensive the No Trespassing sign, the less the danger.
I would say that's generally true. The more expensive the sign, the more likely you're going to have legal problems instead of health problems.
The absolute worst, though, is no sign at all but homemade booby traps. Never encountered any myself, but a former coworker had the pleasure. He was fairly sure that there was a chemistry lab nearby that the owner did NOT want anyone to stumble upon.