Not a bike commute, but a few minutes ago I had an interaction with a couple of plainclothes sheriffs. My walk back from lunch took me through a light rail station; they were staking it out for thieves. They pulled me but let me go in about twenty seconds after I told them where I worked and showed them my work badge.

I don't think I look suspicious. I'm wearing wrinkled Dockers and a t-shirt with a dinosaur on it.