To me the request is no different than if years ago your telephone calling, newspaper & magazine subscription, and TV viewing history - the social contact history of the day - was demanded in order to get a gun.
It’s already done in th Fusion centers. Not sure how often or how masked, but it happens.
I the police, FBI, DOJ, NSA, or DOD have the ability, it is used.
In the military there are many rules that are followed. The non-military agencies? Who knows.