I know of several duck holes being baited by people who didn't hunt them. One was by a guy who just got tired of gunshots waking him up and thought it would shut things down. Moron baited around the blind with popcorn. Hunters realized it before shooting time and called the game warden. Warden explained he was already on his way due to being called by someone else. Hunters, game warden and an irate neighbor met at the launch ramp. Warden figured things out quick (he was a duck hunter and knew popcorn would never be used). Told the hunters to clean it up best they could and start hunting the next day. Told the other guy he would be arrested if anything like that happened again.
Others were baited by neighboring hunters, either a feud or to shut down a spot. One somehow was conveniently rebaited every time the blind owner thought it was clean and called the wardens to check it again. Each time, fresh grain was found. Shut him down the entire season.