Facebook has launched a new tool to allow users to see if they’ve liked or followed Russian propaganda accounts, though the feature probably won’t reach many of the millions of people exposed to fake news during US and UK elections.

Facebook on Friday quietly rolled out a new page that says, “How can I see if I’ve liked or followed a Facebook Page or Instagram account created by the Internet Research Agency?”, referencing the infamous Russian entity and “troll army” accused of trying to influence American elections and British politics on social media.

Because the feature only reveals if users directly liked or followed pages on Facebook or Instagram, it won’t alert users who viewed the propaganda on their news feeds or read the articles without actively following the accounts. The tool is also limited to pages associated with the Internet Research Agency (IRA) and doesn’t include other fake news purveyors.

Facebook and other social media corporations have faced intense scrutiny over the last year for their role in disseminating disinformation and providing a platform for propaganda campaigns meant to disrupt politics across the globe.

Facebook – which testified in front of Congress alongside Google and Twitter – admitted in October that the Russia-backed content reached as many as 126 million Americans on the social network during the 2016 presidential election. The company also recently faced criticisms from the chair of a parliamentary committee in the UK, which slammed the corporation for its weak investigation into the Russian influence on the EU referendum.

The tech giants have faced pressure from members of Congress to actively alert users who may have seen propaganda content, some of which was meant to exacerbate tensions in US politics by exploiting civil rights activism and publishing fake news about hot-button topics. In response, Facebook announced the new tool in November, saying: “It is important that people understand how foreign actors tried to sow division and mistrust using Facebook before and after the 2016 US election.”

Facebook, however, made no announcement on Friday, days before Christmas, when the new page appeared as a link in the site’s help center. A spokesman told the Guardian that Facebook “will make a significant effort to alert people to the tool”, but declined to provide details.

The company has ads on Google directing users who search “Facebook Russian” to its page on “foreign interference” which links to the new tool, the spokesman noted. Regardless of whether people learn of the tool and use it, the feature is clearly limited in scope.

“I commend them for doing this, but I wish they had done this a year and a half ago,” said Brooke Binkowski, managing editor of fact-checking website Snopes.com, which is part of Facebook’s partnership with news organizations to flag false news. Beyond alerting users who followed the pages, she said: “They should absolutely be telling people what they were exposed to.”

Facebook should also alert users to misinformation from sources outside of the Russian propaganda machine, said Binkowski, noting that fake news was still widespread from a variety of places.

It is also unclear how an alert might impact a user who has already been duped by propaganda, she added. “I feel like the people who are going to be taken in by Russian disinformation … are not the type of people who will pay attention to warnings.”