The rest of it is likely the "ability to just pull up data on anyone at any time just cause".

The old school, "we know where you live, what you said to your husband, and that you had marmalade jam with your toast this morning" spy insider knowledge gambit is a strong manipulation tactic whenever you need to convince someone to "just comply".

Having inside knowledge of mundane things that are assumed to be private hold a lot more sway than you'd think. It can make threatening ordinary people a lot easier. Do governments do this often? Probably not, but when they want to interrogate someone, I can almost guarantee they like to be able to pull up everything private they can as leverage in an interrogation.

Is this useful for national security? Probably not, but since when do governments actually care about national security when they can roll around on a power trip and feel big and godly?