If enough people keep getting stabbed in San Francisco, maybe the tourists will stay away! Only slightly not serious. Web search for "stabbing" and "san francisco"
That is surprising. I live in India, and there's no regulation around renting it out or asking tenants to vacate. As long as both landlord and tenant adhere to the agreement document, all is good. No government interference.
Government enforcing regulations asking a landlord that he can or cannot use his home for letting out to a person of his choice seems very regressive to me.