To make generalisations about an entire culture based on things you believe have been done by some members of that culture is bigotted and prejudiced. Disagree with the activity (whether it is domestic violence, theft, violation of planning laws, whatever) certainly but don't try and blame the whole group for it. When that culture largely overlaps with an ethnic group then it tips over into racism. Yes, no doubt, there are some Roma and some Irish Travellers who commit criminal acts. Possibly there is even a higher crime rate in traveller communities than in the wider population (though I suspect that juxtaposition of poor traveller communities near prosperous rural villages may account for a lot of the apparent difference). There are also some offences, such as trespass and breach of planning law, that are encouraged by the actions of the settled community toward travellers. Getting permission to legally set up a site is virtually impossible, and councils rarely meet their obligation to provide suitable pitches. Even when they do they tend to be in appalling locations.