For all our #applenerds out there — a key feature in iPhone has Mozilla worried. According to Ashley Boyd, VP of Advocacy at Mozilla, this key feature is making “their latest slogan ring a bit hollow.”

Each iPhone that Apple sells comes with a unique ID (called an “identifier for advertisers” or IDFA), which lets advertisers track the actions users take when they use apps. It’s like a salesperson following you from store to store while you shop and recording each thing you look at. Not very private at all.

You can turn the feature off, but “most people don’t know that feature even exists.” Mozilla has an idea of “privacy by default” though…