They set up near my mums ex shop at work and the kids constantly tried to steal stuff. They also set up near a bmx track I know and when they left there were huge amounts of rubbish dumped.
I once looked into a travellers camp as I was riding past only to be told I was going to get shot.
I recently passed some at a bus stop in town. As I approached they shouted at me that they wanted my bike and moved towards the road.
There were some young travellers ( about 13 years old ) on a bus recently who hassled a group of teenage girls using obscene language, and tried to stop the bus ( I think by lifting some bodywork outside of the bus between stops ).
Over on pinkbike there was a story of them shooting mtb racers with pellet guns even though the course had been diverted away from the scummy camp.
Their culture seems to be of causing mayhem and waste. I think the ones living in permeant camps may well behave better and be community spirited.
Lovely people. Lets embrace their diversity.