Roughly one hour before the call kicked off, Twitter CEO Jack Dorsey tweeted that his company would stop all political advertising on its platform globally, with the final policy on this matter to be shared Nov. 15.

Fast-growing video-creation application TikTok also said earlier this month that it would not accept political ads on its platform.

Facebook is resisting pressure to follow suit, thus far, despite heavy scrutiny of its policies to allow political ads that contain misinformation and to not subject posts from politicians to third-party fact-checkers.

Zuckerberg repeatedly referenced a speech he gave at Georgetown University earlier this month, in which he reiterated his and his company’s commitment to free expression and giving everybody a voice.

He said in his opening remarks during Wednesday’s earnings call, “Right now, the content debate is about political ads. Should we block political ads with false statements? Should we block all political ads? Google, YouTube and most internet platforms run these same ads; most cable networks run these same ads; and, of course national broadcasters are required by law to run them by Federal Communications Commission regulations. I think there are good reasons for this. In a democracy, I don’t think it’s right for private companies to censor politicians or the news. And although I’ve considered whether we should not carry these ads in the past and I’ll continue to do so, on balance so far, I’ve thought we should continue.”

Zuckerberg also said political ads can be a way for candidates and advocacy groups that aren’t receiving as much media coverage to get their message out, and he discussed the challenges of where to draw the line, adding, “Would we really want to block ads for important political issues, like climate change or women’s empowerment?”

And he cited the transparency measures the social network has built into its platform, including its Ad Library, which enables people on or off Facebook to see every ad that was run by a page, who saw it and how much was spent, among other information.

Zuckerberg addressed the financial implications, saying, “Some people accuse us of allowing this speech because they think all we care about is making money. That’s wrong. I can assure you, from a business perspective, the controversy this creates far outweighs the very small percent of our business that these political ads make up. We estimate that these ads from politicians will be less than 0.5% of our revenue next year. That’s not why we’re doing this. To put this in perspective, the Federal Trade Commission fine that these same critics said wouldn’t be enough to change our incentives was more than 10 times bigger than this. The reality is that we believe deeply that political speech is important, and that’s what is driving us.”

He also discussed accusations that Facebook was using inflammatory content to drive engagement, saying, “I think we’ve done more than any of the other major internet platforms to try to build positive incentives into our systems. We don’t let any of our News Feed or Instagram feed teams set goals around increasing time spent on our services. We rank feeds to encourage meaningful social interactions—helping people connect with friends, family and their communities. We have real people come in and tell us what content they saw that was most meaningful to them and sparked valuable discussions, and then we build systems to try to surface that kind of content. We’ve taken many steps over the years to fight clickbait and polarization, and now, we’re even testing removing like counts in Instagram and Facebook. We do this because we know that if we help people have meaningful interactions, they’ll find our services more valuable, and that’s the key to building something sustainable and growing over time.”

Addressing recent allegations that Facebook is biased toward conservatives, Zuckerberg said, “Some people say this is just all a cynical political calculation and that we’re acting in a way we don’t believe because we’re trying to appease conservatives. That’s wrong, too. We face a lot of criticism from both progressives and conservatives. Frankly, if our goal were trying to make either side happy, then we’re not doing a very good job because I’m pretty sure everyone is frustrated with us. Our values on voice and free expression are not partisan. But unfortunately, in our current environment, a lot of people look at every decision through the lens of whether it’s going to help or hurt the candidate they want in winning their next election.

He concluded, “A lot of people have told us: You’ve got to pick a side, or else both sides are going to cause problems for you. Sadly, from a practical perspective, they may be right. But we can’t make decisions that way. So, over the next year of campaigns, we’re going to be at the center of the debate anytime there’s content or policies on any of our services that people believe could advantage or disadvantage their side. This may lead to more investigations, and the candidates are going to criticize us.”