We’re asking Apple to change the advertising ID for each iPhone every month

It’s true that Apple has an impressive track record of protecting users’ privacy, from end-to-end encryption on iMessage to anti-tracking in Safari. 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. If Apple makes this change, it won’t just improve the privacy of iPhones — it will send Silicon Valley the message that users want companies to safeguard their privacy by default.

Source: blog.mozilla.org