Dozens of FBI officials monitored social media on Election Day 2016 looking for “fake news” being spread as part of a Russian disinformation campaign against former candidate Hillary Clinton, multiple sources told CNN.

The FBI knew it was walking a fine legal line by monitoring the media for “fake news,” according to sources. It was part of a larger effort to look for Russian cyber threats to the elections, CNN reported.

“We were right on the edge of Constitutional legality,” a source briefed on the matter told CNN. “We were monitoring news.”

Intelligence officials monitoring social media held conference calls with the White House throughout Election Day. Some minor issues came up, but nothing happened to disrupt voting.

An anonymous Obama White House official told CNN the election monitoring was “a failure of imagination,” and what the Russians “did worked.”

The news comes on the heels of reports that special counsel Robert Mueller will use at least two grand juries in his investigation into alleged collusion between the Trump campaign and Russian intelligence during the campaign.

To date, there’s been no conclusive evidence of collusion.

Follow Michael on Facebook and Twitter

Content created by The Daily Caller News Foundation is available without charge to any eligible news publisher that can provide a large audience. For licensing opportunities of our original content, please contact licensing@dailycallernewsfoundation.org.