Police around my way take a very dim view of this, and ask you to phone 999.
Last year, they even turned up in the chopper
Any road, the local farmers have taken to doing a nightly patrol to stop the lampers. Basically two of you go out and drive around the area, if you see anybody, you phone two other farmers on your list, they in turn phone two more and so on. Before you know it, twenty or so irrate farmers turn up (with shotguns) and surround said Pikeys, and beleive it or not, they leave. They don't mouth off either.
Soon get the message.
Albeit not very nice, it's not unknown to shoot the Pikey scum's dog(s) either.