Essentially, I believe the three letter agencies are pattern oriented when it comes to tracking.
The more societal functions are automated, the more ways individuals can be effectively screwed and no one in authority can say anything except "well, you were flagged so you must be guilty".
Until we push back against that as well, and then we run right back into the "They came for..." problem.
If you drive from Miami to Montreal, US CBP or Homeland Security has breadcrumbs of your trip the whole way. Camera tracking is possible and is just a matter of funding.
It's already happening. The Chicago Police Department doesn't have to have 70,000 people watching its 70,000 cameras. It just has several dozen. The computer decides if something looks (or sounds — some have microphones) suspicious, then routes that video feed to a human to look at.
The problem is that we train our computers with "AI" (a word we should stop using) that has biases.