Jason Kint is the chief executive of Digital Content Next.

As the Senate prepares to conduct hearings into how Russian actors may have influenced our elections, it is important that our elected officials demand full transparency from the large digital-platform companies — Google and Facebook. Russia's use of digital platforms to manipulate the 2016 election revealed the power these companies now have over our political life, as well as the ways they have dodged the responsibilities that such power brings.

To date, the bulk of public attention has focused on Facebook. But this is not just a Facebook story. This is as much, if not more, about America's gatekeeper to news and information and by far the world's dominant digital advertising platform: Google. As Congress convenes hearings aimed at shedding light on Russia's attempts to interfere in our election, it is crucial that lawmakers demand from Google the full accounting that it has yet to provide voluntarily.

The notion that Russia attempted to influence the 2016 election, but generally neglected Google is, on its face, absurd. Moscow is many things, but ignorant of the digital ecosystem isn't one of them. And Google sits astride the digital world as a colossus.

Google accounts for more than 79 percent of all desktop search traffic and more than 96 percent of all mobile search traffic worldwide. Thanks to its dominance, as well as its influence of the technological infrastructure that delivers ads to other sites across the web, Google now accounts for more than 40 percent of all digital advertising in the United States. In 2016, Google generated $79.4 billion in digital ad revenue worldwide. Google is also the owner of YouTube, which delivers 1 billion hours of video per day and reaches more Americans ages 18 to 49 than any cable network.

So when Russia devised a plan to use digital platforms to interfere in our elections, Google could not have been peripheral. Yet we may never actually know how many political ads Russia or other foreign entities placed on Google during the 2016 election, because, while television stations and cable operators are subject to a wide array of federal oversight, no such rules apply to the king of search.

Why? Because some years back Google told the Federal Election Commission that ads on its platform are character-limited and, therefore, should be eligible for a regulatory exemption originally designed for things such as pencils and buttons that are physically too small to carry printed disclosures. Obviously, there is no physical limitation on a Google ad. Google simply prefers shorter ads. The FEC exemption was granted and the floodgate opened for any entity on the planet to place a political ad on Google with no disclosure requirements at all.

So when Google claimed that Russian agents spent less that $100,000 on ads, how does it actually know that the sum wasn't larger? After all, Google never had to ask whether an ad was political in nature, nor the identity of the purchaser of that ad. The company needs to explain how it determined that number.

In addition, Google shares advertising revenue with the content producers who run ads on their YouTube videos and on their websites through Google's AdSense platform. But the company hasn't disclosed how much money it paid through revenue-sharing to entities attempting to undermine our election.

Over the past few years, Google and Facebook have consolidated their stranglehold over the digital advertising marketplace. Today, nearly 100 percent of all new digital advertising dollars in the United States go to these two companies frequently called the "Duopoly." The companies have skyrocketed in size and influence, in part due to the fact that they deliver an incredible suite of useful and valuable products but also because they are in a position to collect data about consumers at an unrivaled scale across the Internet. But neither company, nor the government have adjusted to the power that the Duopoly has acquired over what information is available and how consumers access it. The nation's focus on the Russia investigation now offers a unique opportunity to restore some balance. Congress needs to demand real answers and real accountability from Facebook and Google.