Buy Nothing is specifically distinct from freecycle, it includes some relatively strict rules, "hyperlocal" groups, and moderators. In my experience, I am confident that this sort of behavior would not be tolerated, assuming it was noticed.

I haven't used my local freecycle group much, because it was stuck on the Yahoo groups platform for so long, but that group seemed much more free-for-all, and not connected to an organized, nationwide project like BN is.