Illustration: Sarah Grillo/Axios

Most data brokers avoid scrutiny by saying the data they collect and sell is “anonymized,” or a summary of a lot of people's information, rather than a single individual’s data.

Yes, but: That "anonymous" data can be used to pinpoint real people, or match that data to other supposedly anonymous profiles.

  • In 2006, AOL released search histories of 657,000 anonymous Americans, hoping the data could spur new research. But those searches contained things like locations, ages and genders — ultimately linkable back to specific people.
  • Researchers like Latanya Sweeney have discovered a variety of other ways to reverse more subtle forms of information. In fact, most Americans can be identified by birthday, gender and zip code, she discovered when she led Harvard’s Data Privacy Lab.
  • Last year, researchers noticed that hashing email addresses — thought to be an anonymizing mathematical function that would turn email addresses into gibberish — could be reversed by taking lists of leaked email addresses and performing trial and error searches.
“Once released, information is hard to control. Thus, over time, the more information and data can be linked and analyzed, the higher the likelihood of being able to make sensitive inferences from it for larger groups of people."
— Alessandro Acquisti, a Carnegie Mellon Professor who has studied re-identification

Go deeper

Updated 5 hours ago - Politics & Policy

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 9:45 p.m. ET: 19,282,972 — Total deaths: 718,851 — Total recoveries — 11,671,491Map.
  2. U.S.: Total confirmed cases as of 9:45 p.m. ET: 4,937,441 — Total deaths: 161,248 — Total recoveries: 1,623,870 — Total tests: 60,415,558Map.
  3. Politics: Trump says he's prepared to sign executive orders on coronavirus aid.
  4. Education: Cuomo says all New York schools can reopen for in-person learning.
  5. Public health: Surgeon general urges flu shots to prevent "double whammy" with coronavirus — Massachusetts pauses reopening after uptick in coronavirus cases.
  6. World: Africa records over 1 million coronavirus cases — Gates Foundation puts $150 million behind coronavirus vaccine production.

Warren and Clinton to speak on same night of Democratic convention

(Photos: Abdulhamid Hosbas/Anadolu Agency via Getty Images, Sean Rayford/Getty Images)

Sen. Elizabeth Warren and Hillary Clinton both are slated to speak on the Wednesday of the Democratic convention — Aug. 19 — four sources familiar with the planning told Axios.

Why it matters: That's the same night Joe Biden's running mate (to be revealed next week) will address the nation. Clinton and Warren represent two of the most influential wise-women of Democratic politics with the potential to turn out millions of establishment and progressive voters in November.

Trump considering order on pre-existing condition protections, which already exist

Photo: Jim Watson/AFP via Getty Images

President Trump announced on Friday he will pursue an executive order requiring insurance companies to cover pre-existing conditions, something that is already law.

Why it matters: The Affordable Care Act already requires insurers to cover pre-existing conditions. The Trump administration is currently arguing in a case before the Supreme Court to strike down that very law — including its pre-existing condition protections.