I emailed the police in North Yorks and was told there had been complaints of travellers photographing horses, nothing about 'european' men and that the nearest to me (Harrogate)was Masham. There hadnt been anything of horses stolen (although I did see something on one of the forums about a mare and foal being stolen in Masham but don't know when so suspect that may be completely unrelated if true) She basically told me to step up our security (already done) and be vigilant
The police are rubbish, I was out riding last week, and was followed for about 2 1/2 miles by two men in a silver/grey estate. They were heavily tanned possibly european, they kept driving past then would park up wait until we got closer and drive away to turn around etc. I got suspcious and trotted to talk to them when they were parked up but they fled.
When I got back I rang west yorkshire and North Yorkshire police we are right on the edge of both. Not very interested took the reg plate and I've heard nothing else.