TL;DR version: a high-end riflescope lets you link to your phone to get images and other data from the scope. A buncha the scopes were illegally exported. .gov is demanding to know who uses the app so they can try and see where the scopes wound up.
This is quite similar to the blanket searches the cops are doing where if someone gets shot in XYZ neighborhood they demand the phone records of everyone who was in that are at the time and then they troll through that info looking to see if they recognize a suspect.
The solution to these rather broad and offensive assaults on privacy, other than politely walking these people to the end of a long pier and giving them a strong pat on the back, is not to discard your smartphone but rather acquire one that isn’t attached to your ‘real life’. Theyre a tad more expensive, but burner smartphones that don’t require ID might be worth it. And, of course, never leave your phone with the battery in it anyplace where you’re going to be spending a lot of time.