They do here in the UK. It's like a low blanket fog. When I lived in Dundee one day they done it during the day. It was an icy fog that came in from the sea. Everyone was taking pictures but I seen it happen from the Dundee mount (monument overlooking the city). I think those offshore carriers that are always hanging around are the ones that do that. Also sometimes the sprayers get too low. You'll have fog/mist but you can tell it's unnatura and looks like particles instead of natural fog/mist.