Comment It is a public safety issue (Score 5, Informative) 149
As soon as money changes hands it is no longer a "private arrangement". When you charge for a place to stay you are now a hotel unless it is on a month to month basis then you have a roommate. If you are providing the same service as a hotel you are operating a hotel. It is not a "public safety" issue.
This summary is inaccurate - it is a "public safety" issue. In the Nigel Warren case where he rented out his room on Airbnb in NYC, the judge levied a fine of fine of $2,400 after ruling that they were operating an unlicensed hotel.
The law on which the decision was based, Bill S6873B-2009 states:-
JUSTIFICATION:
The Multiple Dwelling Law and local Building, Fire and Housing Maintenance Codes establish stricter fire safety standards for dwellings such as hotels that rent rooms on a day to day (transient) basis than the standards for dwellings intended for month to month (permanent) residence. There are substantial penalties for owners who use dwellings constructed for permanent occupancy (Class A) as illegal hotels. However, the economic incentive for this unlawful and dangerous practice has increased, while it is easier than ever to advertise illegal hotel rooms for rent to tourists over the internet
... It endangers both the legal and illegal occupants of the building because it does not comply with fire and safety codes for transient use.
I.e. The reasoning given for the law was to protect public safety, specifically to ensure compliance with fire and safety codes.