"Airbnb's website tells people to check local laws and their leases. A specific section on San Francisco explains the prohibition on short-term rentals and link

"Airbnb's website tells people to check local laws and their leases. A specific section on San Francisco explains the prohibition on short-term rentals and links to various city codes." So why doesn't AirBnB simply disallow listings from SF? Worried that will impact their valuation?