This follows the news from yesterday that Facebook has detected evidence of an influence campaign targeting the elections, which will be held in November of this year. The company wasn't able to pinpoint the source of this coordinated effort, but there are enough links to Russian accounts to make an educated guess.

It seems as though these campaigns weren't overly influential, but it doesn't change the fact that the Senate Intelligence Committee is concerned. It's not clear who will testify from each company, but Bloomberg reports that Facebook COO Sheryl Sandberg will likely be attending the hearing.