The biggest U.S. broadband companies financed a “secret campaign” in 2017 to generate millions of fake public comments to the Federal Communications Commission to provide cover for the regulator’s planned repeal of net neutrality rules, New York’s top law enforcement officer said.

A four-year investigation by the state concluded that the companies hid their involvement in the effort, which resulted in 18 million bogus comments out of 22 million total on the hot-button issue, New York Attorney General Letitia James said in a statement Thursday.

In a Republican-led vote in 2017, the FCC swept aside the net neutrality rules that barred broadband providers from favoring partners’ internet traffic.

It later rejected calls to delay ending the rules, saying it hadn’t relied on suspicious submissions. Ajit Pai, then FCC chairman under President Donald Trump, said the move would “restore internet freedom.”

“Nearly every comment and message the broadband industry submitted to the FCC and Congress was fake, signed using the names and addresses of millions of individuals without their knowledge or consent” James, a Democrat, said in the statement.

The comments “did not reflect people’s real viewpoints, with more than 8.5 million of those comments using the names and personal information of real people without their knowledge or consent.”

New York said in its report that the campaign was run through the nonprofit group Broadband for America. The organization lists members including AT&T Inc., Charter Communications Inc. and Comcast Corp., as well as trade groups CTIA, which represents large wireless carriers, NCTA–The Internet & Television Association, and USTelecom-The Broadband Association.

None of the companies or trade groups immediately responded to emails seeking comment on the report.

FCC Acting Chairwoman Jessica Rosenworcel, a Democrat appointed by President Joe Biden who supports net neutrality rules, said the report shows the agency acted on a record that “was flooded with fraud.”

“This was troubling at the time because even then the widespread problems with the record were apparent,” Rosenworcel said in a statement. “We have to learn from these lessons and improve because the public deserves an open and fair opportunity to tell Washington what they think about the policies that affect their lives.”