Or places with collateral damage due to failures of German ISPs and state... That is many other parts of Europe while roaming... 4GB is significant cut of the roaming data allocated...

Some time ago friends were pranking each other with 32GB favicon.ico files this was a thing and one of them was on mobile in Germany. Turns out it would keep downloading in the background even if leaving the page. Their account was locked and had a massive bill for roaming charges. That prank went horribly wrong.