Three United States senators led by Elizabeth Warren have sent a letter to Binance CEO Changpeng “CZ” Zhao and Binance.US CEO Brian Shroder expressing concern over a number of facets of Binance’s activities and requesting information from the companies that includes their balance sheets. 

Crypto skeptic Warren’s cosigners were fellow Democrat Chris Van Hollen and Republican Roger Marshall. They claimed there is evidence that the companies attempted to evade U.S. regulators, evade sanctions and facilitated the laundering of at least $10 billion, and lack transparency.

“What little information about Binance’s finances is available to the public suggests that the exchange is a hotbed of illegal financial activity,” the senators wrote, concluding:

“Your companies’ apparent attempts at evading the enforcement of anti-money laundering laws, securities laws, information reporting requirements, and other financial regulations cast serious doubt on the stability and legitimacy of Binance and its related entities, and on your commitment to your customers.”

The senators requested documents and other information. At the top of the list is “all Binance and Binance subsidiary balance sheets from 2017 to the present.” In addition, they ask for copies of Anti-Money Laundering and similar policies, documentation of the relationship between Binance and Binance.US and other information, as well as explanations of various news reports. They gave the addressees two weeks to respond.

Related: Sen. Warren vows reintroduction of AML bill that extends to DAOs and DeFi

As the letter made clear in its 59 footnotes, Binance has been the object of intense press scrutiny and a certain amount of negative speculation. CZ, a prolific tweeter, has responded to some reports personally. It was reported in February that Binance was preparing to settle outstanding regulatory and law-enforcement issues in the United States and would possibly be subject to penalties.