Wouldn't it be great to put an electrical charge in the sign so when they touch it........they get zapped? Not enough to do permanent damage, just enough to give them a wake up call......
I have heard, though I have no direct knowledge of this, of course, that one person wiped axle grease on the back side of his sign, after reinforcing the edges with duct tape. I have about 500 signs out in 40 precicnts, and it's getting expensive to keep replacing these things.