They've been convicted of fraud. They had hundreds of millions seized from bank account of criminals which they helped launder money for. They cannot operate in NY anymore and the NYAG fined them. I think Canada banned these fraudsters too?
They also sold Moonstone bank to SBF/FTX which illegally siphoned money out of the US to the Bahamas.
Nothing smells of fraud as much as tether/Bitfinex. Not even Madoff.