Greenland is part of the Kingdom of Denmark, but not of the EU. They would either have to separately apply for EU membership or ask the Kingdom to do something about it.

Can there really be an objective measurement? You should think first thing data harvesters would implement is a sort of cloak, to erase any traces of what’s going on. Think Dieselgate, but more sophisticated. E.g. phone detects it’s being tested the way you described, or is in the hands of a state attorney or whatever, the recording/ forwarding/ prcoessing of data stops.

Same here. Confidential discussion with lawyer/ doctor/ pharmacist, get extremely relevant ads at once. Therefore, I made it a habit to completely turn off my phone before entering such situations, and, if I can, put it in a switched-off microwave or some other Faraday cage structure, Snowden-style.