There's only so much runny foodstuff you can fling at glass-fronted paintings before people stop paying much attention. They say they're not afraid of the cons

There's only so much runny foodstuff you can fling at glass-fronted paintings before people stop paying much attention. They say they're not afraid of the consequences but I'd like to see them try thier luck irreversibly destroying a national treasure in some major oil producing country not known for its sense humour about such matters.