DjBeau Not just the phone number from the sim card, but other hardware identifiers as well, like IMEI.

      DjBeau I tried creating a Google account without phone number by making a new user through GOS. It works, but there's no other way to do it. So I'm wondering if it's working because google is simply grabbing the number from the SIM card?

      On GrapheneOS that would require Play having been granted the Phone permission.

      Google's account-creation system uses a variety of heuristics. If an account is created using a residential IP address, for example, a phone number might not be required.

        secrec

        Google software tends to be very secure, as security is one of Googles strengths.

        You can read the long message by de0u with sources to GrapheneOS's twitter posts saying the same as me above.