I agree that it would take to much manpower, time, to search everybody all the time.
But, “persons of interest” would be the target. And persons of interest would be defined by those with power and by what/who is bothering them.
At any given point it could be you, given that you’re intelligent, capable of communicating, and not afraid of organizing.
I would expect anyone with the capacity to get together groups of people to be of interest.
That is why we have the FISA courts.