WASHINGTON (AP) — As Congress bears down on big tech companies, two senators want to force giants like Google, Facebook and Amazon to tell users what data they're collecting from them and how much it's worth.

The legislation was floated Monday by Sens. Mark Warner, D-Va., and Josh Hawley, R-Mo.

It comes as bipartisan support grows in Congress for a privacy law that could sharply rein in the ability of the biggest tech companies to collect and make money from users' personal data. At the same time, a House panel has opened a bipartisan investigation of Silicon Valley's market dominance.

The bill goes to the heart of the tech giants' lucrative business model: harvesting data from platform users and making it available to advertisers so they can pinpoint specific consumers to target.