In the first high-profile attempt to block the FCC’s rollback of net neutrality rules through the courts, 22 attorneys general have filed a lawsuit challenging the agency’s repeal plan.

The lawsuit is led by New York Attorney General Eric Schneiderman

Led by New York Attorney General Eric Schneiderman, the petition asks a court to find that the FCC’s plan runs afoul of federal law.

“An open internet — and the free exchange of ideas it allows — is critical to our democratic process,” Schneiderman said in a statement announcing the suit, filed on behalf of 21 states and the District of Columbia. “The repeal of net neutrality would turn internet service providers into gatekeepers — allowing them to put profits over consumers while controlling what we see, what we do, and what we say online.”

The lawsuit, brought in front of the US Court of Appeals for the DC Circuit, asks the court to determine that the FCC’s repeal is “arbitrary, capricious, and an abuse of discretion” under the law. The suit will also argue that the FCC wrongly reclassified broadband as a so-called Title I information service — rather than a Title II service — because of “an erroneous and unreasonable interpretation” of communications law. Public interest groups announced simultaneously that they had also filed petitions.

The lawsuit from the attorneys general says it was filed “out of an abundance of caution,” as the petitioners say the FCC’s rule should be officially published before lawsuits are brought. In case a court decides on a different timeline, however, lawsuits are being filed now.

Consumer advocacy group Public Knowledge similarly said in an announcement that it had filed “a purely procedural move” challenging the rule, even though it believed the FCC’s rules still need to be officially published before a suit can be brought. Mozilla also announced a suit.

Meanwhile, the Senate is attempting to pass a measure that could block the FCC’s plan. But that attempt faces unlikely prospects, as it would also need to survive the House and receive President Trump’s signature. The hopes of many net neutrality advocates, then, will hinge on a successful lawsuit.