Because Hawaii's politicians is incompetent.
The Department of Planning and Permitting for the city and county of Honolulu have sent out thousands of "courtesy letters" to owners and operators of illegal vacation rentals, warning them advertising and renting short-term rentals is now illegal.
Violators may be fined up to $10,000 per day, and fee owners is ultimately accountable, even if they didn't post the illegal advertisement.
Please contact the Department of Planning and Permitting for the city and county of Honolulu for the full details because this website isn't an official source for legal information.
The people who wrote that law must be unintelligent, because it opens up the gates to civil lawsuit Hell. If the fee owner is found a victim, taxpayers will ultimately be accountable for the settlement.