Senators Mark Warner (D-Va.) and Josh Hawley (R-Mo.) will introduce legislation on Monday to require Facebook, Google, Amazon and other major platforms to disclose the value of their users' data, as first reported Sunday evening on "Axios on HBO."Why it matters: Our personal data is arguably our most valuable asset in the digital age, but internet users don't have any way of knowing how much their data is actually worth. The big picture: Two decades ago, consumers made a bargain — we traded our data in exchange for using "free" sites like Facebook, Instagram, Google, YouTube and Twitter. Warner says he wants consumers to be more informed about the real value of what they give up in the form of, for example, location data, relationship status, data about the apps we use, our age, gender and lifestyle. "These companies take enormous, enormous amounts of data about us... If you're an avid Facebook user, chances are Facebook knows more about you than the U.S. government knows about you. People don't realize one, how much data is being collected; and two, they don't realize how much that data is worth."Sen. Mark Warner on "Axios on HBO"Between the lines: The point of the bill is to help consumers understand what they may be giving up when they click on "I agree" and hold tech companies to a higher level of transparency.Individuals wouldn't get any sort of pay-out for the use of their data.The value of an individual's data is the subject of some debate. Warner says it's probably around $5 a month, while other estimates put it around $20 a month. It could be more, depending on the type of data collected. How it works: The legislation will be introduced Monday as the Designing Accounting Safeguards to Help Broaden Oversight and Regulations on Data Act, or DASHBOARD for short. The bill would require companies that generate material revenue from data collection or processing — and have more than 100 million monthly users — to disclose to users the types of data collected, how it is used, and to provide an assessment of the value of that data once every 90 days. It would require these companies to disclose annually to the Securities and Exchange Commission the aggregate value of all of their users' data. The report would have to include details of contracts with third parties for data collection, how revenue is generated by user data, and measures taken to protect that data.The bill would direct the SEC to develop methods for calculating the value of user data, accounting for varying uses, sectors, and business models. Companies must provide a setting or tool for users to delete all or part of their data.The other side: Tech companies are reluctant to disclose specifics of how users data is gathered, shared and sold. There's little chance they'll be interested in putting a dollar figure on how much that data — the core of their business — is actually worth to them. Some have argued it's not possible to calculate the exact value of specific pieces of data in a high-volume marketplace across an industry that uses data across dozens of platforms, all delivering different services with different business models. "Boloney," Warner said of that defense. "I mean if these companies — go back to Facebook — can do all these acquisitions and many of these acquisitions were made on what appeared to be outrageous prices — they had a pretty darn good notion of how they could use that data and how much that was worth from one platform to another."Despite more aggressive calls to break up Big Tech, Warner said he's not yet sure that's necessary, as long as Silicon Valley is receptive to more tailored measures like this bill. Warner told "Axios on HBO" he plans to introduce a separate bill "in a few weeks" that would require tech firms to make data portable so consumers can move it from one platform to another. He's also sponsored legislation to improve online political ad disclosures, and to ban social media sites from tricking users into giving up their data."If they're not willing to work with us on this kind of, I think, rational, focused reform, then I may very quickly join the crowd that simply says, 'you know, let's break them up,'" he said. "And I say that as somebody who was a technology entrepreneur longer than I've been a senator."The bottom line: "This senator's patience is wearing very thin. It's time for these companies to put their money where their mouth is."Go deeper: Axios' Deep Dive on Data Privacy