More than 20 state attorneys general on Tuesday kicked off the first major legal battle over the Federal Communications Commission's decision to repeal its net neutrality rules.

Attorneys general from 21 states and the District of Columbia, including New York, California, Connecticut, Delaware and Pennsylvania, filed a petition for review of the decision at the U.S. Court of Appeals for the District of Columbia. The state AGs argue the FCC's Jan. 4 order restoring the framework for regulating internet service providers to what it was in 2015 is arbitrary and capricious under the Administrative Procedure Act.

“An open internet—and the free exchange of ideas it allows—is critical to our democratic process,” New York Attorney General Eric Schneiderman said in a statement. “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. This would be a disaster for New York consumers and businesses, and for everyone who cares about a free and open internet.”

A spokesperson from the FCC did not immediately respond to a request for comment. In defending the vote to repeal the rules last month, Republican FCC chairman Ajit Pai said the internet will remain open to all Americans.

“Following today's vote, Americans will still be able to access the websites they want to visit,” Pai said. “They will still be able to enjoy the services they want to enjoy. There will still be cops on the beat guarding a free and open Internet. This is the way things were prior to 2015, and this is the way they will be once again.”

The states plan to argue the new rules unlawfully pre-empt state and local laws about net neutrality, and wrongly reclassify broadband internet as a Title I information service instead of a Title II telecommunications service, which would subject ISPs to certain regulations under the Communications Act.

State AGs were not the only ones to go to court over the issue Tuesday. In a blog post, internet company Mozilla also said it would file a petition in the federal court in Washington, as did the nonprofit group Public Knowledge.

In June 2016, the D.C. Circuit upheld the President Barack Obama-era rules that barred internet service providers from blocking certain content or slowing down internet speed, after twice remanding the issue to the agency.