In 2013, just 12 percent of people asked copped to watching internet porn at all. But thanks to pervasive online tracking and browser fingerprinting, the brazen liars of America may not have a say in whether their porn habits stay secret. Porn watchers everywhere are being tracked, and if software engineer Brett Thomas is right, it would be easy to out them, along with an extensive list of every clip they've viewed.

Thomas, who lives in San Francisco, recently found himself at a bar, chatting with a member of the online adult-entertainment industry. They got to talking about economics, naturally. While the porn professional insisted that collecting and selling the personal data of users who visited erotic websites wasn't part of the industry's business model, Thomas wasn't convinced.