New burner phones, probably, but one could exit from a flea market or 2nd hand shop with a €100 bagful of phones not linked to anyone, at least until one puts p

New burner phones, probably, but one could exit from a flea market or 2nd hand shop with a €100 bagful of phones not linked to anyone, at least until one puts personal data inside them or creates a potential association by using the same phones along personal ones on the same WiFi/cell tower/position or calling the same numbers.