They were eventually officially banned at Hell Survivors. Now it's a gentleman's agreement sort of thing. If Weltman found himself behind me, he'd give me a smile, safe in the knowledge that i'd take it like a man. I wouldn't smile up a stranger, but someone I knew or in a game where the word was out that they'd be present? I'd go for it, though I always mark the mask and not the throat. For us they were just what they would be in real life, a silent weapon for someone you have the complete drop on from behind.
I always called it smiling as lipstick on adhesive felt was the best marking agent by far.
We play Pistol and we encourage the Few despite the discouragement of the Many.