Airbnb, which ginned up a heavy-handed astroturf campaign to try to block city regulation of short-term rentals, is now trying another approach: A lawsuit charging Boston with heavy handedness of its own by attempting to violate both Airbnb's and its affiliates' free speech and privacy rights.

In a complaint filed in US District Court in Boston today, the company says its listings are not its own products and that it is the publisher of a Web site used by third parties to advertise their rooms and condos to the public.

As a publisher, Airbnb says, it is protected from any government action over those listings by third parties. And because it's a publisher, the city can't require it to share what it says is confidential information with its customers - which in this case means the people and companies that use its platform to offer short-term rentals.

Another national site, Backpage.com, has long used the same argument to frustrate law-enforcement agencies investigating the trafficking of minors.

In June, the City Council passed, and Mayor Walsh signed, an ordinance, set to go into effect Jan. 1, that would ban investor-owned short-term rental units altogether and set up a series of registration and notification requirements for people renting out such units. For example, owners of units rented out would have to register with ISD, notify adjacent unit owners.

The ordinance would also require Airbnb and other booking services to delete any listings of ineligible units - for example, units facing city health or building violations or which had not been registered with the city.

It's these requirements that most offend Airbnb. In its complaint, the company says:

Airbnb believes that home-sharing may be lawfully regulated, and it has worked with dozens of cities to develop the tools they need to do so without violating federal or state law. Boston’s heavy-handed approach, however, crosses several clear legal lines and must be invalidated. The Ordinance, for example, compels Airbnb to enter into undefined so-called "agreements" with the City that will require Airbnb to take down listings posted by third-parties and prevent whatever scope of listings in whatever manner Boston dictates - or else be barred from Boston altogether. The Ordinance also forces home-sharing platforms like Airbnb to actively police third-party content on their websites by penalizing the design and operation of their platforms and restricting and imposing severe financial burdens on protected commercial speech. And it requires Airbnb to disclose to the City confidential information about its users without any legal process or precompliance review. This regime violates the Communications Decency Act (47 U.S.C. § 230), the Stored Communications Act (18 U.S.C. §§ 2701 et seq.), the First, Fourth, and Fourteenth Amendments of the U.S. Constitution, and the Massachusetts Declaration of Rights.

The complaint continues:

The Ordinance is inconsistent with the CDA because it (i) requires Airbnb to remove (and prohibits the publication of) certain third-party rental advertisements; (ii) directly regulates the structure and operation of Airbnb’s platform; and (iii) requires Airbnb to monitor, review, and verify that third-party content. By imposing these obligations and duties on Airbnb, and costly liability for failure to comply, the Ordinance impermissibly treats Airbnb as the publisher or speaker of third-party content. The CDA therefore preempts the Ordinance. The Ordinance apparently attempts to evade the preemptive effects of the CDA by requiring Airbnb to enter an "agreement" to undertake the offensive monitoring and removal activities. That is not an "agreement" - it is compulsion. The Ordinance also violates the First and Fourteenth Amendments of the U.S. Constitution and Article 16 of the Massachusetts Declaration of Rights because it is an impermissible content-based regulation of speech. The Ordinance also violates the Stored Communications Act, 18 U.S.C. §§ 2701 et seq. (the "SCA"), the Fourth Amendment, and Article 14 of the Massachusetts Declaration of Rights by requiring Airbnb to turn over personal, non-public information about its hosts. The City cannot obtain this data without legal process and precompliance review. In attempting to do so, the Ordinance breaches critical privacy protections.

The complaint asks that a judge strike the registration and reporting requirements of the ordinance, at least as they apply to Airbnb, and to award the company attorneys fees.