While Twitter and Facebook publicly quarrel about whether they should keep political ads on their sites, one big voice has been noticeably absent from the debate: Google.

Google parent Alphabet gets 84% of its revenue from advertising, with an increasing amount coming through its YouTube video platform. As of last month, YouTube was stepping up its efforts to lure political ad dollars away from television and Facebook with new tools for advertisers.

But we didn't hear a peep from Google this week, even as Jack Dorsey announced that Twitter would ban political advertisements, swiping at Facebook's Mark Zuckerberg, who said on his company's earnings call that it's not the job of a private enterprise to "censor politicians and the news." Facebook's controversial ads policy was a major point of contention during Zuckerberg's recent testimony to Congress.

Despite its size and influence, Google has managed to escape the same level of scrutiny. Consider the recent attack on Facebook for running an ad from Trump's reelection campaign containing false allegations about Joe Biden's activity in Ukraine. YouTube and Twitter also ran the ad but dodged the heavy criticism.

A Google spokesperson said that the company doesn't have "special exceptions" for political ads and that all ads that run on its platform have to comply with its ads policies. The spokesperson wouldn't say whether that meant political ads are fact-checked to ensure compliance with its "misrepresentation" policy, which doesn't allow ads that "intend to deceive users," and wouldn't explain why the Trump campaign's Biden ad didn't violate these policies.

One big difference with Google is that President Trump and other politicians are less visible there than on Facebook or Twitter, where they send constant messages — true or not — to their supporters and followers. Those sites are driven by news feeds that cater to political groups who can mask their paid messages and make them appear to be actual news.