I'm saying, good. As long as they can't track everyone (or a significant fraction of everyone), and as long as we're talking about information that was already subject to surveillance (so, for instance, explicitly not talking about where your actual body is walking around inside buildings &c)... this seems like a good thing. LEOs are generally starved for resources. This seems like a common sense win to me.
(a) it's a symptom of a larger problem, and
(b) the larger problem isn't "law enforcement is in the long term just a system for allowing a couple thousand people unlimited access to anal cavity searches on arbitrary citizens".
$10000: Use GPS trackers never, send patrolmen instead. We agree that this is suboptimal.
$500?: Tag more people of interest than you could do on foot, involving some-but-not-many unrelated persons.
$100?: Tag more vehicles, with a concomitant rise in data collection not related to any current investigation.
$1: Tag every vehicle related even tangentially to an investigation, just on principle. This I would not approve of - how about you?
From that I conclude that there's some lower price bound at which the freedom/security tradeoff turns against us. I don't think we're there yet - I don't disapprove of anything reported in the article. But it'll happen eventually, and we should figure out how those laws should work before there's a de facto standard in law enforcement, because that standard will be "use them every time". Police work is terribly hard as it is; any further handicaps that we feel we need to impose must have the force of law behind them.
It's probably not legal though for a private citizen to plant tracking devices on people however.