> Buildings should be able to opt out, and airbnb should respect it, and ban users that misuse it.

I think this is the part that kinda irks me though. Why would any building, township, city ever opt-in? You're specifically asking the people who have every incentive to say no while completely ignoring the renters and tenants who actually benefit from the transaction.

If you only ask the people who own property near where the city wants to build a new highway color me surprised when it's a resounding no.