Obv. there are regional differences, about closed shops, or whether all employees are in a union, or places where `=no` isn't a bad thing (right?), or whatever. This can't cover everything.
obv. I'm thinking of things like consumer facing cafés here, rather than things like a car factory, or hospital, or things like that. My idea may, or may not, be relevant here. Please feel free to correct me.
@amapanda What about small family businesses where being in a union doesn't make sense? I appreciate your good intentions, but make sure it doesn't inadvertently harm someone innocent.