The US Senate Commerce Committee has voted to subpoena the heads of Google, Facebook, and Twitter.
It means that Sundar Pichai, Mark Zuckerberg and Jack Dorsey face being quizzed by senators about their policies on different types of content.
One focus will be legal protections they enjoy in regard to what they leave up and take down on their platforms.
They are also likely to be challenged over controversies about privacy and misinformation.
Republicans and Democrats on the committee voted unanimously to summon the chief executives.
“There has never been such an aggregation of power in the history of humankind as big tech enjoys today, with money and monopoly power and the hubris that comes with the unchecked use of power,” Republican Senator Ted Cruz said following the vote.
Amazon, Apple, Facebook and Google’s chiefs testified to a House committee about competition issues and claims of bias.
The congressional report into that event is expected to be published next week.