Executives from Facebook, Twitter and Google are facing two hearings in Congress today, including the Senate Intelligence Committee.
The social media execs are facing questions about political intrusion, antitrust concerns, censorship and consumer privacy.
Lawmakers from both sides want the tech giants to explain how they are protecting the 2018 midterm election process from interference from Russia.
Thirteen Russians were indicted earlier this year on charges of an elaborate social media plot to disrupt the 2016 US presidential election.
"The companies have made progress, the government has made progress, but the bad guys have made progress as well," said Sen. Mark Warner (D-VA). He wants new regulations for these companies.
On another big issue, conservatives contend that Twitter and Facebook often censor their messages.
"Sadly, conservatives are too often finding their voices silenced," House Majority Leader Kevin McCarthy said in a statement. "We all agree that transparency is the only way to fully restore Americans' trust in these important public platforms."
The House Energy and Commerce Committee hearing will focus only on bias by Twitter and the platform's algorithms.
Twitter CEO Jack Dorsey says in pre-released House testimony that his company does not use political ideology to make decisions.