Microsoft co-founder Bill Gates took aim at cryptocurrencies during a Reddit "Ask Me Anything" session Tuesday – much to the ire of some social-media commentators.

Responding to a question about cryptocurrencies, the world's second-richest man said the ability of governments to track money laundering or terrorist funds “is a good thing.”

Gates continued, saying:

Naturally, the crypto world was not impressed by this answer.

Reactions on Twitter immediately began dissecting the response on both semantic and technical grounds.

Venture capitalist Anthony Pompliano pointed out that cryptocurrencies are not strictly anonymous, and said the same concerns Gates stated could be applied to traditional fiat currencies.

"He spewed the normal nonsense about funding terrorism & money laundering," Pompliano said of Gates.

Bitcoin developer Udi Wertheimer agreed, saying “cryptocurrencies didn’t cause deaths in a ‘fairly direct way’ any more than cash did.”

A moderator of the /r/bitcoin subreddit provided a more detailed response, pointing out that “the main feature of cryptocurrencies is their immutability and their ability to support trustless transactions,” rather than anonymity.

Know-your-client and anti-money laundering laws also make it difficult for users to anonymously cash out their cryptocurrency holdings, which should discourage the purchase of illegal goods, the user said.

Other users simply laughed. Neeraj Agrawal, Coin Center’s head of communications, joked that Gates was a “broke nocoiner,” while @WhalePanda said the billionaire had joined the “old man yells at bitcoin” list.

User @DanDarkPill identified a positive use case for bitcoin, telling Gates that he had bought a banana.

Not every response was as harsh. One Twitter user said it was understandable that someone as rich as Gates would not bother to thoroughly research "some internet money scheme."

This is not the first time Gates has criticized cryptocurrencies for lacking transparency.

During another AMA in 2014, he commented that the Bill & Melinda Gates Foundation was working on a digital form of money but "unlike bitcoin, it would not be anonymous."

However, at the time he was far more optimistic about bitcoin, saying that "bitcoin is better than currency in that you don't have to physically be in the same place, and of course for large transactions currency can get pretty inconvenient."

He was more cautious in 2015, saying that while he saw the potential for cryptocurrencies like bitcoin to make a huge impact, he did not think bitcoin specifically would become a payment system of the future.

Bill Gates image via Frederic Legrand - COMEO / Shutterstock