Not sure. Maybe they can't. I've only busted two of them, and the one that got ugly, I reported to AB&B, they recognized it as a fake profile and yanked her. The other went off without a hitch, but I'm sure she got fleeced, as it was a zero vacancy weekend in town. So I was just theorizing that they could leave a bad review, but you make a very good point, I don't think they can if they're not the actual "guest", but they seem to know that they're in on some kind of a nefarious deal, because their stories are loose variations on what the "agent" said in the inquiry, yet with even more glaring descrepencies. It is still uncomfortable to have someone show up expecting 2 bathrooms, two parking spots, and with two extra guests and wondering how much they actually paid. Still, it's not cool to have people in your house that haven't gone through verification processes, becasue some of them might be using agents to get around Instant Booking qualifications or to circumvent some review that they got from some disaterous stay with some other poor host.