San Francisco CNN Business  — 

Bill Gates waded into the debate over political ads on social media platforms during an interview Wednesday, calling for some limitations while also siding with those who say the companies should not play the role of fact-checker.

In the lead up to the 2020 US elections, Facebook (FB) and Twitter (TWTR) have been under intense scrutiny over how they handle misleading or false political ads. They’ve been criticized for not subjecting such ads to fact-checking by third parties, instead leaving it to the media and users to flag falsehoods.

Gates, for his part, says the problem is how political ads might be tailored and targeted with messages that will never be viewed beyond a small audience.

“I think that targeting, in that domain essentially, should not be allowed,” Gates said at the The New York Times’ DealBook conference. “It’s the targeting where you don’t see the hate ad that just appeals to that one person. It’s the targeting that’s really screwed this thing up.”

However, he said he doesn’t think the platforms should be responsible for policing the content of these ads.

“I wish I thought that was such a thing that could be done,” he said. “I disagree with people who think that a corporation should sit there and do fact-checking against those things. Yes, there are extreme cases somebody can come up with like Holocaust denial or various things. But, no, no private company can or should make those judgments.”

In response to criticism and concerns over the issue, Twitter announced last week that it would stop accepting political ads altogether starting November 15. CEO Jack Dorsey tweeted that Twitter believes “political message reach should be earned, not bought.” But even that policy has raised questions over what constitutes a political ad.

Facebook CEO Mark Zuckerberg has so far staunchly defended his company’s decision to continue to run these ads. Zuckerberg said he doesn’t believe private companies should censor politicians or the news in a democracy. However, he said he would “continue” to evaluate Facebook’s policy on political ads.