[danShumway]

I'm not sure why this is downvoted.

WiFi can be used to track most people's phones because they'll have personally identifiable networks they're set to auto-connect to. Randomizing the Mac address is not enough to prevent tracking in that scenario.

Unless Apple has some way to guard against this that I've never heard of? But I don't think they do.

JohnFen's root comment is totally wrong (Apple is encrypting your location so even they can't read it), but on the WiFi side of things this seems spot on to me. Turn your WiFi off when you leave your house.