To be fair, that’s a weighted vest that a lot of (mostly Crossfitters functional fitness types (I don’t want to get sued)) wear to make their workouts harder.
There's no real such thing as a true bullet proof vest, unless you enjoy wearing 25lb steel plates; a ceramic armor vest is significantly lighter but are not rated to take more than a few impacts of 7.62mm or even a few 9mm for regular consumer grade restricted for non-military use armor
Nobody is going to sue you for making fun of CrossFit. If they try, just show the court a video of people thrashing around with kettlebells and I think any judge would agree that CrissFitters are fucking stupid.
For women, wearing a weight vest actually legitimately helps reduce bone loss in the hips. Statistically marked improvements for women tested vs control group.
Source - Snow CM, et al. Long-term exercise using weighted vests prevents hip bone loss in postmenopausal women. J Gerontol A Biol Sci Med Sci 55(9); M489-491, 2000