(Apologies if the answers to the following questions seem obvious, but I am not an expert, so thought I'd ask.)
The larger question can be broken down, but I don't believe the subquestions are worthy of separate SE questions, so here goes:
1. True or false: when one puts any Android device in airplane mode, one disables all signal transmission from the device.
I believe the answer to this is true, but would be interested to know of, e.g. (in descending order of interest),
- the extent to which this statement is not true for all Androids OOTB. E.g., are there specific makes/models for which this statement is not true?
- the extent to which one or more Android devices can have airplane mode turned off by an external signal. Example scenario which comes to (my paranoid :-) mind:
- could a private anti-theft service, presumably with matching app, ping a device such its app takes the device out of airplane mode to respond?
- do any governments require devices purchased in their jurisdiction require to respond to some external signal?
2. True or false: any Android device which cannot transmit signals cannot be geotracked.
Again, I suspect this to be true, but would be interested to know about non-trivial ways in which it might be false. An example of a non-trivial defeat would be a device that has a factory-installed passive RFID tag. An example of a trivial defeat would be for a user to attach a GPS beacon to her/his device.
If both of those are true, then one cannot (trivially) geotrack the location of an Android device in airplane mode ... unless I'm missing something ...