It's easy to maintain accountability: any damage done can be trivially traced back to the party that did it. Anyone that opens up a disgusting mess will just r

It's easy to maintain accountability: any damage done can be trivially traced back to the party that did it. Anyone that opens up a disgusting mess will just report it, and that will be tied to the previous user. This is already how car-share programs work. Each time you use a Zipcar, you look around for any damage and claim it. If you forget, you might be held responsible. If it's really a problem, then people might not mind placing a sizable deposit to use a service where that's discouraged even more. Or accept that they'll be recorded for the duration of the trip, etc. I agree it's an issue, but it seems like one that can be effectively mitigated.