Comment by kristianbrigman

Key word is always. It's not just about being observed (with or without knowing when and by whom), but also having no control over it.

Craiglist-mediated exchange is a choice. School, prison or workplace is not - not in any practical sense.

I don't think I've ever met in a public place for Craigslist trades. I've always gone to the seller's house. I don't think we've ever sold anything, but when we put something up for free online we just leave it outside and tell them to come get it.