Neither your link, the article from OP, nor the actual NLRB memo mentions ankle bracelets.

> For example, employers ... track [workers'] movements using wearable devices

2nd paragraph of GP's link.

> Abruzzo’s memo cites things like wearable devices for warehouse workers

6th paragraph of OP article.

I don't think the commenter meant literal ankle bracelets. But I think that's a bit pointless. I don't think it's okay whether it is a literal ankle bracelet, or some BLE tag in their badge. Do you think some option is okay?

> The distinction between a supervisor watching their employee vs. cameras + CV vs. using wearables to automate the watching seems completely arbitrary to me.

I'd be pretty weirded out by constant camera and CV monitoring too

> Are you OK with a cab company monitoring its cars via GPS? Or a trucking company monitoring its loads via tracker?

Those are (a) not monitoring a person and (b) much more coarse than "what shelf is this person standing in front of". They tell the company that the cab driver parked, not that the cab driver took exactly 3 minutes and 33 seconds in the restroom.

I suppose my biggest concern with it is that it's measuring the wrong thing. If someone's doing as much as their coworkers even though they leaned on a shelf for 5 minutes yesterday, is that really a problem?

By comparison monitoring a car with GPS has legitimate purposes that actually advance the interests of the business.

The fascination with ankle brackets notwithstanding (does a badge worn at the ankle count? How bout an ankle bracelet obscured in the pocket?) I hope the safety aspects dominate anything like that. How many people are in the mine? How many minutes was each employee exposed to over 90 dB?