Well, they may become tenants anyway by operation of law in some jurisdictions based on the length of stay -30 days or so. Once on sits as a guest, they can refuse to sign a private agreement and or a legal lease and demand tenant rights no matter what based on length of stay! this is an issue that must be resolved in hosts' specific jurisdiction. As a group of Airbnb hosts we need to get together to change the tenancy laws in the cases where guests are using Airbnb to gain access to vacation/regular rental properties without the applications, screening, rental agreements, addendums, deposits etc. required of legitimate rental applicants. This is a burgeoning issue throughout the country. It is harmful to hosts, neighbors, businesses, and Airbnb itself! The laws must be changed to address this serious issue - right now, it is a murky situation where Airbnb guest rules intersect with tenancy rights and obligations once a guest meets the 30 day benchmark and begins to use tenancy rights without the obligations required had that guest gained access as a renter applicant and followed jurisdictional laws for a legal tenancy. As a guest who has a qualifying stay length to become a tenant does not seem to have a valid lease. I know that Portland, Oregon acknowledges a 30 day stay guest as a tenant, but says tenant is to follow the rules in their Airbnb contract up to the end of their stay. If they stay after the stay is over, tenancy laws are the only way to evict and Airbnb is no longer responsible - though, Airbnb does try to help. I will not take any more reservation nights beyond 28 nights with check out on morning of 29 day. Be sure to keep all communication on Airbnb messaging.