There Is No Such Thing as "Public" Data

That's the argument made by a group of Danish researchers who released a data set on nearly 70,000 users of the popular dating website. The researchers used an automated tool called a "scraper" that captures parts of a webpage--a possible violation of the website's terms of use. These users had answered questions on intimate topics like drug use and sexual preferences. The researchers took no steps to deidentify the data set when they released it, despite it being possible to reidentify many of the profiles. When the researchers were called out about this lapse on Twitter, one of them shrugged it off with the flip statement "Data is already public."