AT&T took an unusual step in an effort to block a campaign that seeks to stop its proposed $39 billion merger with T-Mobile: suing its own customers.

AT&T filed eight lawsuits last week alleging that Bursor & Fisher, the firm behind the “Fight The Merger” campaign, and Faruqi & Faruqi, a second plaintiff’s firm, are pushing the company into “an extortionate settlement,” according to a Reuters report. AT&T said the firms’ efforts to get customers to file multiple claims against it over its proposed merger with T-Mobile forced its hand.

The arbitration campaign, which began in July, urges AT&T customers to fight back against the merger on the grounds that it may violate federal antitrust law and stifle competition.

In an earlier interview with Post Tech, Scott Bursor, the lawyer leading the arbitration campaign, said that about 1,000 people have joined the movement through its Web site requesting to be assigned an arbitrator in their local county. Bursor said the group had heard from customers in 47 states and 800 counties across the country.

According to the report, the firm has filed 26 arbitration demands and more than 900 notices of dispute.

AT&T argued in the lawsuits that these claims, filed under antitrust law, could not be settled by arbitration, the article stated.

The company has said that its arbitration agreement, recently upheld in the U.S. Supreme Court case AT&T v. Concepcion, only allows for individual relief for individual claims, and cannot be used in broader claims.