Well, I think technically you may be right Rosco. I have thought a lot about this also. My son and I do a lot of door knocking and hunt a lot of yards. But we have to realize that the city probably does not maintain that area, mowing etc...the person that lives there does. If a big thing is made about leaving if told to, then you will be remembered in the future by the cop. Not worth the hassle. I just go up to the door and ask the people if they mind if I hunt on the "PUBLIC AREA" out by the sidewalk and the street. They almost always don't mind. The great thing about just asking is you might just get to hunt the whole front yard also. It's horrible to try and hunt looking over your shoulder all the time wondering if you're going to get ran off. The worst that can happen is they say no, Hey, there's many other places to hunt anyway. It's looking out the window or door and seeing someone by surprise in what they consider "their yard" since they maintain it, that gets them defensive. Also the city could pass a new city ordinance against metal detecting if they had to many problems or complaints if they really wanted to. That would really stink. Anyway...Good Luck...Dickie