Meet victim in club/bus/supermarket/wherever

I'm not an expert, but I don't think this is how stalking works in practice. People don't stalk random strangers they meet in the supermarket. They stalk former partners, and (more rarely) people they've developed an obsession about. That means the stalker has to worry about being recognized by the victim, and consequently will have fewer opportunities to plant a device and retrieve a device than you imagine.

Furthermore, while being tracked for up to 96 hours indeed is a frightening thought, the typical stalker's goal is to track their victim at all times. Having to plant and retrieve a device at least every four days, without being detected by the victim, makes for a very impractical way to achieve that goal.

    I'm not an expert, but I don't think this is how
    stalking works in practice. People don't stalk random 
    strangers they meet in the supermarket. They stalk
    former partners, and (more rarely) people they've
    developed an obsession about.

However, if not properly safeguarded, this sort of tech clearly can enable some new types of bad behavior.

Ultimately I'm a technology optimist and we shouldn't reject new tech simply because it might be misused. However it's also true that even the most cursory glance at history shows us that just about any new technology is also used for nefarious purposes.

But of course as I linked in another comment, trackers have been fit into anything and everything now. Hairbrushes, random trinkets like clocks, even a phone charging brick itself