If they abide by the law of the land then there will be no problem trisher. However, it is the taxpayer who is the victim here not the travellers.
For instance, Exeter City Council paid out nearly £20k moving traveller groups off their land over two years, 17 encampments across eight locations, lasting for a total of 118 days and consisting of 106 caravans. These encampments 'on city council-owned land used by the public, is causing distress to users and nearby residents. And the same sites may be re-revisited and often barriers are cut or fences uprooted to gain access'. There was anti-social behaviour and intimidation. Clearing up after them is a major problem.
I could go on but you get the idea. This is just one location, but it's happening all over the country.