Ex-Twitter employees are suing Musk’s social media business saying the company not only failed to pay them promised severance, but then delayed their arbitration cases by failing to pay filing fees.

X, the social network formerly known as Twitter, is facing 2,200 arbitration cases that ex-employees filed after Elon Musk took over the company, slashed headcount, and made other sweeping changes there. The filing fees alone for that volume of cases could amount to $3.5 million.

The arbitration numbers were revealed in a new filing out Monday as part of a lawsuit in a Delaware district court. The case is Chris Woodfield v. Twitter, X Corp. and Elon Musk (No. 1:23-cv-780-CFC).

As CNBC has previously reported, many large corporations require workers to sign an arbitration agreement upon employment wherever it is legal to do so. This means to speak freely in court, where their speech can become part of a public record, workers would first need to get an exemption from a judge.