If you have wifi turned on then what's to stop you being tracked. I imagine Google Maps can track you using a combination of GPS and WiFi, as well as working out your likely route between locations for periods you're out of contact.
Precisely. With any outgoing connection, your phone is constantly looking, reporting, and talking. IIRC, didn't Google (or maybe even some Open Initiative) do a huge mapping of routers based just on the MAC and overlays with GoogleMaps or OpenStreet?
A connection exposes you to surveillance, and yes, it's worse with SIMs, but having WiFi on just adds a little latency to the same thing. Public Routers that you're discovering do the same thing. I had thought this was the entire point of iOS devices randomizing their MACs when scanning available networks (no idea if this ever got shipped with Android devices).
I am probably in the "nutty" quadrant when it comes to concerns about tracking, surveillance concerns, and online privacy, but I also don't really like needlessly inconveniencing myself just to undermine the entire purpose of why the inconvenience is necessary in the first place. Your phone is always talking -- SIM card or not. I'm not even sure modern non-smart phones (flip revivals and such) are wifi free.
Such protections are a good ideal, but a lot of people have an unrealistic idea of the threat actors they're trying to protect against.
