I don't think I'd be able to tell if someone was going to turn out to be a bad home. My screening is to talk live on the phone with anybody before I give them my address. If their voice/speech/phone manners gives me the creeps, then I would just find some excuse to tell them no, and not give my address. I do realize that that's really not much of a screening process. But so far I've found most people who are willing to actually speak turn out to be (SEEM) pretty nice. A lot of the text-only types never make it to the phone call stage, and that's just as well.