I am not sure where dog owners got the idea that it is okay to walk their dogs on the neighbor's lawns which is private property. Yes, you may, or may not, clean up after your dog but the residue is still there and more importantly the scent is there signaling other dogs that it is okay to go there. Even worse you are killing the grass that took so long to try to grow and made to look presentable. Please respect other people's property.