While here in Germany, the P'keys soon move on when plod turns to, might have something with them all being armed & quite happy to use a baton on miscreants.
https://www.thelocal.de/20170811/irish-travellers-struggle-to-find-campsite-in-rhine-region
Same in France DinG, they turn up in a village or small town, within 30/40 mins the Police are there - not the normal Gendarmes but the rough lads with body armour, big, big sticks and guns - the unwelcome mass depart very quickly. Why, Why can't we effectively control these incidents, where others are left to clear up the mess they leave behind them?