The U.S. Securities and Exchange Commission sued to freeze the assets of an initial coin offering that claimed to have raised almost $600 million.

The restraining order halts AriseBank from raising any additional cash from investors, according to a complaint unsealed Tuesday in federal court in Dallas. For the first time, the agency is seeking to freeze crypto assets including bitcoin, dogecoin and litecoin among others.

The asset freeze is the biggest action yet for the agency trying to police a red-hot market that’s raised billions from mom-and-pop investors. The regulator has been sounding the alarm about the offerings, which are most likely securities that must be registered to comply with U.S. securities laws.

Can Bitcoin Be Regulated? U.S. Courts Are About to Decide

AriseBank claims to be one of the largest cryptocurrency platforms ever built, according to the complaint.

This article was provided by Bloomberg News.