Twitter CEO Jack Dorsey announced by tweet on Wednesday that the platform will ban all political advertising. Later that same day, Facebook CEO Mark Zuckerberg explained to investors why Facebook would never make such a move during a call to discuss third-quarter earnings. In a jiu jitsu-like battle in which the two have locked horns without ever mentioning each other's names--or even the social media platforms they lead--each has made his argument in the forum of public opinion, leaving those of us who use either or both platforms to make up our own minds.

The short versions of their positions: Zuckerberg says banning political ads would amount to censorship. Dorsey says there's a distinction between censoring a message and not accepting money to promote that message. Dorsey also says that in this era of micro-targeting, political advertising on social media can do and has done a great deal of harm. Zuckerberg hasn't explicitly said so, but Facebook's efforts to remove ads and posts by Russian operatives shows that he knows full well how much damage such ads can do. So does Facebook's new policy forbidding ads that discourage people from voting, despite the company's anti-censorship stance. That came about because in 2016 Russians ran Facebook ads suggesting that people "protest" by either not voting or by voting for the Green Party candidate, and targeted them to African-Americans.

Zuckerberg used part of his earnings discussion with analysts to explain his thinking, in direct response to Dorsey's announcement, even if he didn't mention Twitter or Dorsey by name: "Some people accuse us of allowing the speech because they think that all we care about is making money, and that's wrong," Zuckerberg said. In fact, he added, Facebook projects only half a percent of its advertising revenue will come from political ads in 2020. Instead, the decision comes from his belief that in a democracy, private companies should not censor politicians, he explained. "Ads can be an important part of voice--especially for candidates and advocacy groups the media might not otherwise cover so they can get their message into debates."

As for Dorsey, he laid out his argument against allowing political advertising in a lengthy series of carefully crafted tweets. He explained:

"While internet advertising is incredibly powerful and very effective for commercial advertisers, that power brings significant risks to politics, where it can be used to influence votes to affect the lives of millions. Internet political ads present entirely new challenges to civic discourse: machine learning-based optimization of messaging and micro-targeting, unchecked misleading information, and deep fakes. All at increasing velocity, sophistication, and overwhelming scale."

 And then in a fairly direct dig at Zuckerberg and Facebook, he tweeted this:

So far, both the media and the Twittersphere seem to be siding more with Dorsey's approach, perhaps because they're weary of political slur messages or wary of Russian interference in the 2020 election. But one very big detractor was Brad Parscale, campaign manager for Donald Trump's 2020 presidential bid. In a tweet, Parscale called the new rule "a very dumb decision." He speculated that the ban was aimed at silencing his boss, and might be rescinded as soon the 2020 election is over.

Of course, it's likely that neither of these CEOs is motivated purely by sentiments about democracy. By announcing the political ad ban, Dorsey created a lot of goodwill and also distracted everyone from the other recent news about Twitter which is that its revenues and profits both tanked in the third quarter. And Zuckerberg, whose company is currently under investigation by the Federal Trade Commission and possibly also the Justice Department, may not want to do anything that could anger the Trump administration right now.

Which of them is right? I guess it's up to users, and voters, to decide.