Update (May 26 at 9:30 pm UTC): This article has been updated to include statements from The Digital Chamber.

The Digital Chamber, a cryptocurrency advocacy group that has been closely involved in negotiations with US lawmakers over digital asset-related legislation, questioned three-term Massachusetts Senator Elizabeth Warren’s understanding of banking laws as applied to crypto companies.

In a Tuesday letter to the US Comptroller of the Currency (OCC) Jonathan Gould, Digital Chamber CEO Cody Carbone challenged many of the claims in the Massachusetts lawmaker’s May 18 letter. In that letter, Warren said that the OCC may have violated the National Bank Act by approving national trust charters for nine crypto companies “that intend to…