It doesn’t look like it’s on one flimsy pin or something, and shirts can be strong, I think just yanking it off would be hard.

Probably more or less the same effect as if you grab a handful of someone’s shirt and give a quick tug. The shirt wouldn’t tear unless it’s tear-away lol. You’d just end up yanking the fella.

But it might just be these are with some magnets or smth and just have gps on them so you could yank it but would need to put it in a Faraday cage to isolate it idk