At the TechFestNW event in Portland on Friday, Oregon Sen. Ron Wyden called for legal reforms that embrace an understanding that the mere act of handing over digital data doesn't mean giving way a user's right to privacy.

"Some will still argue that by sharing data freely with Facebook, Google, Mint, Uber, Twitter, Fitbit or Instagram, Americans are choosing to make that data public. But that is simply not the case," the Democrat said, according to prepared remarks released by his office. He added, "When I send an e-mail to my wife, or store a document in the cloud so I can review it later, my service provider and I have an agreement that my information will stay private. Neither of us have invited the government to have a peek."

What Wyden, long a spirited privacy advocate, is pressing for is reform of the so-called "third-party doctrine," or the idea that by releasing data to another person, business or entity one gives up some Fourth Amendment protections. The doctrine is rooted in the 1979 Smith v. Maryland decision, in which the Supreme Court found that telephone users had no reasonable reason to believe that their calling records are private. "We doubt that people in general entertain any actual expectation of privacy in the numbers they dial," the court found then. But what's more, held the court, privacy is eroded by the knowledge that such data is used for "a variety of legitimate business purposes," like for the processing of billing, for example.

The concept, though, takes on new light at a time when both data forms the basis of the business models for so many modern companies, from Uber to Instagram, and when government have an ability to collect and process data not reined in by technological limitations. And so, argued Wyden, it must be limited by law.

In Portland, Wyden ticked through possible solutions — ending bulk collection of the data of Americans, clarifying the lines between law enforcement activities and intelligence gathering, passing the GPS Bill on geo-location data he is championing with Rep. Jason Chaffetz (R-Utah) — but mostly Wyden was at TechFestNW to give language to an idea fairly newly in the air, from the June Supreme Court ruling that held that cellphone searches generally require a warrant to an on-going case about the protections that apply to an American citizens' e-mail data stored in a Microsoft facility in Ireland.

Wyden is attempting here to stuff it all into a coherent framework, even if he's not exactly sure yet what that might be. "Applying the Founding Fathers' principles to the age of high-tech digital surveillance," the senator argued in Portland, "is going to require some new thinking"