The social media company will inform lawmakers this week of the number, which CNN notes is the equivalent of over half of America's total voting population.
CNN obtained a copy of written testimony to the Senate Judiciary Subcommittee on Crime and Terrorism. According to the outlet, Facebook General Counsel Colin Stretch says 29 million people received content directly from the Internet Research Agency, a troll farm linked to the Russian government. Stretch says that, when user sharing is taken into account, "approximately 126 million people" may have seen the content.
Facebook emphasises that although 126 million people were exposed, not all of them necessarily read the posts or even logged onto the platform on any given day. In its testimony, the company says the Russia-backed posts represent "a tiny fraction of the overall content on Facebook."
"This equals about four-thousandths of one percent (0.004%) of content in News Feed, or approximately 1 out of 23,000 pieces of content," Stretch states in the testimony. "Put another way, if each of these posts were a commercial on television, you'd have to watch more than 600 hours of television to see something from the IRA."
Lawyers for Facebook, Google, and Twitter will appear in public hearings this week to answer questions regarding how Russia used their platforms to meddle in the 2016 election.
Both Facebook and Twitter have emphasised that the Internet Research Agency-linked content represents a small portion of their platforms' content and have stated they're taking steps to prevent future interference. But lawmakers will likely focus on both the content and the reach of the Russia-backed posts during the hearings.
"Most of the ads appear to focus on divisive social and political messages across the ideological spectrum, touching on topics from LGBT matters to race issues to immigration to gun rights," Stretch writes in the testimony. "A number of the ads encourage people to follow Pages on these issues, which in turn produced posts on similarly charged subjects."
The Russian-bought Facebook ads will likely be released to the public later this week.