There is a way to sus them out: https://www.404media.co/this-app-warns-you-if-someone-is-wea...
Not perfect, but better than nothing I guess. I don't think I've noticed the glasses IRL anywhere, but if I start seeing them, I'm definitely installing the app and avoiding any interactions with those people.
they look like big bulky ray-bans that no one would wear unless they were starring in a 50s remake or something . easy to spot