The senators in question are Missouri Republican Josh Hawley, who you may remember as the champion of the proposed "Protecting Children from Abusive Games Act" (which would ban loot boxes in games aimed at kids), and Virginia Democrat Mark Warner.
In broad strokes, the politicians' proposed legislation, which has been dubbed the Designing Accounting Safeguards to Help Broaden Oversight and Regulations on Data Act (DASHBOARD Act), would force big tech companies to quantify exactly how much their users' data is worth and disclose the results publicly.
Senator Josh Hawley.
In order to avoid putting undue stress on a given company's operations, the Act would only require companies to perform this data value audit every 90 days. Furthermore, it won't be entirely up to the companies to determine data values; the SEC will be responsible for creating specific guidelines for them to follow. This should make the data calculation process a bit easier for corporations, while also ensuring they can't fudge numbers.
It remains to be seen whether or not the DASHBOARD Act will gain any traction, but the fact that it has bipartisan support right out of the gate is interesting, at the very least.