Booby traps are illegal, so removing it definitely isn't. You're not even allowed to booby trap your own private property. If someone gets hurt from a booby trap the victim hold the responsibly party liable for their damages and injuries. Not to mention the environmental hazard, razor blades to hurt people, pets, and animals. Special kind of scum to force people and animals to have to deal with razorblades in their local parks when inevitably weather disintegrates them and the posters are never retrieved.