> On the other every model of iPad/iPhone on the same OS version should have the same fingerprint Not quite. For example, they might be on different networks,

> On the other every model of iPad/iPhone on the same OS version should have the same fingerprint Not quite. For example, they might be on different networks, have different zoom levels set, etc. > Doesn't Safari do this already? Last I checked, Safari "blocks" (not quite; it's double-keying, not actually blocking) some third-party cookies, but not all. In particular, it doesn't block third-party cookies from sites you have visited in a first-party context. So for example it doesn't block Facebook or Google trackers. The Firefox "no third party cookies" mode, which actually blocks all third-party cookies, is quite different from the Safari behavior...