privacy

I don't think that's a problem, but I suppose it depends on your goals. Facial recognition in low-light conditions is already hard enough of a problem that they, presumably, are not building IR-light-clothing detection into their algorithms. And if IR-blasting clothing becomes commonplace enough that they start working on it, then it's also no longer distinctive. So, if the goal is to defeat passive surveillance of your movements, this should be highly effective.

If a human reviews the footage, then none of this likely matters anyway, since they'll be able to identify other identifying features about you—but that's a scalability problem. You'd need to have done something very "interesting" to be worth investing the time into tracking across hundreds of video feeds through a surveillance network.

If your goal is to get away with a crime or actively resist detection while protesting, then this is (obviously) a bad idea to wear this. You should instead choose something as non-descript as possible, like all black, long sleeves, gloves, face mask, and tinted goggles. But you can't just walk around in public like that, in general.