Mayor Bill de Blasio and the City Council tightened the screws on New York's booming "home-share" market yesterday, with the mayor signing a bill that could dramatically reduce the number of apartments available on websites like Airbnb while also making information on hosts available to the city.

"This law provides the City with the critical data it needs to preserve our housing stock, keep visitors safe, and ensure residents feel secure in their homes and neighborhoods," said Christian Klossner, executive director of the Mayor’s Office of Special Enforcement, in a statement.

The law splits public opinion. Airbnb, of course, opposed it from the start, arguing that many New Yorkers rent their apartments to earn much-needed supplemental income. In an open letter, the company also suggested that city councilmembers—who unanimously passed the bill in mid-July—may have been influenced by campaign donations from the hotel industry. (The Hotel Association of New York City, a lobbying group, has been on the offensive against companies like Airbnb, even going so far as to suggest that that Airbnb aids and abets terrorists.)

The New York Civil Liberties Union, meanwhile, has raised privacy concerns over the way the law requires Airbnb and similar sites to provide host names, addresses, and contact information to the Mayor's Office of Special Enforcement, along with details on when, how long, and for what fee those people rented out their spaces.

The City Council, however, maintains that the legislation actually helps protect low-income city-dwellers, who find themselves priced out of the housing market possibly (or at least partially) because Airbnb encourages people to rent their homes to visitors and tourists instead of residents. Councilmember and bill sponsor Carlina Rivera said at the signing ceremony that the law would allow the city "to go after the most egregious operators." In the city's eyes, these bad operators include companies like Big Apple, which is at the center of a lawsuit that illuminates a lot of this conflict.

New York sued Airbnb, TripAdvisor, and on July 20th, arguing that Big Apple had repurposed 26 rent-stabilized units into temporary (and illegal) sublets. That violates the New York State Multiple Dwelling Law, which bars people from letting their apartments for fewer than 30 days, unless those permanent occupants are present. The vast majority of Airbnb profits nationwide, and 75% of the company's revenue in New York alone—currently its largest market, with 50,000 listings—come from whole-unit rentals that likely violate state law.

Under the new law, home-share platforms face either a $1,500 fine or one year's worth of rental fees for the unit in question, every time they fail to turn over the requested host information. It goes into effect in February 2019.

In a statement, Josh Meltzer—Airbnb's Head of Northeast Policy—said the company was "disappointed" in de Blasio's decision to "sign this hotel industry-backed bill instead of defending the needs of middle class New Yorkers who rely on sharing their home to get by."

"While the Mayor himself has said regular New Yorkers should not be the target of enforcement, many responsible homeowners are currently facing aggressive, unchecked policing, and are fearful of what will happen under this new legislation," the statement reads. "As we continue to advocate for our host community across the five boroughs, we hope to work with the Mayor to create common sense regulations that finally distinguish these families from the few bad actors who should feel the full force of the law."