JPMorgan Chase CEO Jamie Dimon attacked Bitcoin and other cryptocurrencies on Wednesday, suggesting that they’re only useful for criminals and may as well be banned.

“If I were the government, I’d close it down,” Dimon said of the crypto industry during remarks on Capitol Hill on Wednesday.

Bitcoin, Banks, and Crime

Dimon was one among several CEOs of the eight largest U.S. banks to testify before the Senate Banking Committee on Wednesday at a hearing concerning annual oversight of Wall Street firms.

His comments were in response to questioning from senator Elizabeth Warren (D-MA), a notorious congressional crypto skeptic, who asked why crypto has become “such an attractive financial tool for terrorists, drug traffickers, and rogue nations.”

“I’ve always been deeply opposed to crypto, Bitcoin, etc,” answered Dimon. “The only true use case for it is [for] criminals – drug traffickers, anti-money laundering, tax avoidance… and that is a use case.”

The CEO argued that crypto is handy for these purposes since it is “somewhat anonymous,” offers instantaneous transactions, and inherently bypasses all of the restrictions of banking institutions regulated by the government, which are subject to anti-money laundering (AML), know-your-customer (KYC), and sanctions laws.

Senator Warren followed with a plea for Congress to update existing banking rules to apply to anti-money laundering rules to crypto companies, to which several other banking CEOs agreed. It marked a rare point of solidarity between Warren and the executives, with the former historically known as a harsh critic of the banking industry.

Dimon’s Distaste for Crypto

Dimon’s opposition to crypto is nothing new, however. Throughout the past two years, the banking CEO has told investors to “stay away from Bitcoin,” claiming that it has “no intrinsic value,” and is a “decentralized Ponzi scheme.”

Earlier this year, Dimon said he didn’t believe that Bitcoin’s trademark supply cap of 21 million coins was actually real.