If all these men are claiming all these women are out to get them and make false statements, they would have already been using every tool available, hence they would have been wearing some form of body cam prior to this. They are simply saying it now, because it's way more discreet to use these glasses and potentially use them for other purposes.
If you are using cameras for some kind of defense, you make them loud and proud, not super discreet. They are designed to be a visual deterrent so the possible crime is less likely to happen in the first place.