Not sure if outdated but it sounds totally worth it for Airbnb if they can attract a few more customers.

Penalties for Hiring Undocumented Immigrants

You may be subject to civil and criminal penalties for hiring undocumented immigrant workers. Civil penalties range from a minimum of $375 per unauthorized worker for a first offense up to a maximum of $1,600 per worker for a third or subsequent offense. If you are found to have engaged in a “pattern and practice” of hiring undocumented workers, then you can be fined up to $3,000 per employee and/or imprisoned for up to six months.
(source)
http://www.nolo.com/legal-encycloped...mmigrants.html