In fairness, they used to take the tops of pop bottles to stop them being thrown. You can kinda understand it.
They should serve free tap water though, even bloody Disney does that and they get you for literally everything
Let’s not forget us Yanks are also being robbed.
At MLB games, which are played in summer heat it’s not against any rules to bring in your own water as long as the bottle is unopened. This has FIFA written all over it.