Tether has been accused of using a commuting bank for it essentially using a bank account that is not prescribed for one use for another. The theory here is that the d o j is probing whether tether did this to move money. And they basically admitted it in a youtube clip that i believe bit finext has shared multiple times on their twitter handle. This is an ample of, once you start committing any kind of fraud or fugase activity, and you get on regulators' radar, it never ends.