Bluebella - I really do sympathise as daughter lives near Cottenham in Cambridgeshire which also has a similar problem to those near Witham etc in Essex.
However, both of these sites are illegal ones where travellers have either bought the land themselves and illegally developed it or just squatted.
Perhaps if the Government provide well regulated and more suitably sited sites (sorry), these big, no go area, sites would not proliferate.
It was more the tone in which the question was posed which grated : as though "these" people were a sub-species.