Sorry for starting another thread like this
My personal opinion is this behaviour is selfish. A small bottle or can of drink (singular) or a personal snack (e.g crisps) is fair game to be removed from the lounge. But not something in its entirety which is clearly intended to be shared between anyone using the lounge.
I don't think there's anything BA can or should do to prevent it, but as mentioned above it does shows character.