I have to side with hollowpointred on this. I too, like him, have seen and heard of people who get "no's", where ......quite frankly .... no one had ever cared before! Yup, parks or schools that had been detected since the dawn of detectors, in full view of anyone and everyone, and no one ever cared. So in those cases, who's giving detecting a "bad name"? Who's the one getting places "put off limits"? It seems to me it's the persons who feel they need to ask permission (merely implying that it needs it) that do the hobby a dis-service.
And for those of you who cite instances where you got "yes's", I gaurantee you, you will not always get those, and simply nix yourself out of sites that no one would ever have paid you any mind to. And to those parks/schools you got a "yes" on, I gaurantee you that I could get your "yes" reversed just as quickly. I (as a "concerned citizen") could have a quick talk with that desk clerk. I just mention "ARPA", "digging", the "taking of other people's lost valuables", "potential lawsuits", etc.... In other words, I bet, with the right combination of mental images, your "yes" can just as easily turn to a "no". So best just to think of yourself as no different than any other park user. To think otherwise, you've already lost the battle.