No, I am giving you an alternative story about the nails holding the sign on the side of the road. You feel it OK to violate the Civil Rights of people and get all pissy when they defend themselves. I hate to tell you little boy but when you break the law you get to pay the consequences of those actions. I can make a legitimate argument for the purpose of the nails holding the signs.
Guy, your profound ignorance of the law is no excuse.
I would recommend you look up
Bodine v. Enterprise High School. It didn't matter the kid was on the roof playing a prank... the school allowed an unsafe condition to exist and ended up paying him for the rest of his life.
Even if you could make an argument for putting nails in a board that were facing up, (you cant), it was still an unsafe condition you allowed to exist. If someone had been injured as a result, youd be liable, not them.