Finestrino Bloccato
Italian railway operator Trenitalia has a simple way of locking the windows shut in some of its older carriages with (retro-fitted?) air-conditioning. This was on a train from Florence to Pisa; the sticker probably cost more than the screw. I like that.
It also allows passengers who really need some air to unscrew them – perhaps if the air-conditioning fails, or indeed otherwise – as a couple of people had done.
