Mueller said to interview "at least one" Facebook employee

Special Counsel Robert Mueller's team investigating Russian meddling in the 2016 election has talked to "at least one" Facebook staffer, Wired's Issie Lapowsky reported on Friday. The employee reportedly worked with Donald Trump's presidential campaign. Both Mueller's office and Facebook declined to comment.

Why it matters: It further embroils the world's largest social network in the controversy around Russia's meddling in the 2016 campaign, and is more evidence that Mueller is interested in Trump's digital operation.