Facebook CEO Mark Zuckerberg's recent speech at Georgetown University defending Facebook's free speech policies, including the decision to allow false and misleading political ads, has garnered a lot of criticism. The CEO's 40-minute address, which invoked Martin Luther King Jr., Frederick Douglass, and the history of the First Amendment to defend Zuckerberg's belief in “giving people a voice,” has come under fire from civil rights leaders, members of Congress—and, now, one of his best-known colleagues in Silicon Valley. Twitter CEO Jack Dorsey was asked about Zuckerberg's speech during a conversation at the Twitter News Conference in New York Thursday, and the fellow social media exec made it clear he had some issues with what he called a “major gap and flaw” in Zuckerberg's argument. “I think he had points that I agree with,” Dorsey said. “I think the more important conversation is what was left out.”

Dorsey said Thursday that he took issue with Zuckerberg equating all kinds of speech on Facebook's platform, which is curated through an algorithm that promotes certain posts to a wider audience. More controversial posts that get more comments and reaction as a result might be shown to more people, for instance, and there's a clear difference between “earned reach,” meaning posts that naturally go viral, and “paid reach” from promoted posts. That Zuckerberg didn't address this distinction, Dorsey said Thursday, “was a major gap and flaw in the substance he was getting across.” “We talk a lot about speech and expression and we don’t talk about reach enough, and we don’t talk about amplification,” Dorsey said. “And reach and amplification was not represented in that speech.”

The Twitter CEO also judged Zuckerberg's decision to seemingly revise Facebook's origin story in his speech, as Zuckerberg suggested he was inspired to create Facebook at Harvard University by the Iraq War. “I remember feeling that if more people had a voice to share their experiences, maybe things would have gone differently,” Zuckerberg said. (In actuality, Facebook's origin story more often gets linked to Zuckerberg's desire to rate female students' attractiveness, and early Facebook users have pointed out the first iteration of the site didn't have communication features that would have enabled users to debate the war.) “There’s some amount of revisionist history in all his storytelling,” Dorsey said of Zuckerberg. “It takes away from the authenticity and the genuineness of what we’re trying to do.”

As Zuckerberg moves forward with Facebook's plan to enter the cryptocurrency game with Libra, Dorsey said Thursday in no uncertain terms that Twitter won't be signing on to the widely-scrutinized venture. When asked whether Twitter would join the suite of companies that will join Facebook in the Libra Association, Dorsey had a clear response: “Hell no.” “It’s not an internet open standard that was born on the internet,” Dorsey explained. “It was born out of a company’s intention, and it’s not consistent with what I personally believe and what I want our company to stand for.” But though the CEO was clear he had issues with Libra as a cryptocurrency—“They use that label liberally...I don’t know if it’s a gimmick, but cryptocurrency wasn’t necessary to make that thing work,” Dorsey said—he was more enthusiastic about decentralized cryptocurrency more generally, and cryptocurrency's place in the online community. “I think the internet is somewhat of an emerging nation-state in almost every way,” Dorsey said. “It almost has a currency now in the form of cryptocurrency and bitcoin.”