When I lived out in the country, there were several folks that were quite serious about others dumping their trash on their property illegally. Not only did this dumping make their land look trashy (yea, that's kind of a pun, but is also serious) but the sheriff was happy to fine the land owner for the illegal trash, even if they knew nothing about it.
One land owner was able to photograph someone dumping on their land and gave the info to the sheriff, who proceeded to do absolutely nothing about it. He later collected all of the trash that was illegally dumped and delivered it to the home of the owner of the vehicle that did the dumping. When the city PD where the dumper lived showed up asking about his dumping all that trash, he showed them the pictures and stated that he was just returning those items to their owner. The PD was good with that but said "No more dumping, please", to which the land owner said "If they stop their dumping, I will have no reason to return the items to them.".