“Computer scientists have developed an algorithm that can pick out almost any American in databases supposedly stripped of personal information,” is the overline on this New York Times article about the relative ease of identifying supposedly anonymized data. And “there are mountains of anonymized data circulating worldwide, all of it at risk,” the author writes.
And this story helpfully contains a link to another story about how private genetic information may not be all that private after all. This story was from 2013, which is eons ago in terms of how technology and database science have advanced since then.