"This tool will be available for use by the end of the year in the Facebook Help Center."

On Wednesday, Facebook announced that it would create a "portal to enable people on Facebook to learn which of the Internet Research Agency Facebook Pages or Instagram accounts they may have liked or followed between January 2015 and August 2017."
The Internet Research Agency (which the New York Times Magazine extensively profiled in 2014) is believed to be a pro-Kremlin troll farm that helped create false politically themed pages.

"This tool will be available for use by the end of the year in the Facebook Help Center," Facebook continued.

The social media giant has been under increased scrutiny given that Russia seemingly used online ads to stoke various political opinions and possibly influence the 2016 presidential election. The issue of Russian digital influence has been so troubling and potentially so widespread, Congress even called top officials from Facebook (as well as Twitter and Google) to testify in front of the Senate Judiciary Committee in October. "This is a national security challenge of the 21st Century," Sen. Lindsey Graham (R-S.C.) said during the hearing.
Even with the upcoming portal, The Wall Street Journal notes that more than 100 million other Facebook users who encountered those pages’ ads or posts, or who may have liked, shared, or commented on those pages, will not be notified.

Facebook did not immediately respond to Ars’ request for comment.