This article denouncing Nick Clegg and David Blunkett for worrying about Sheffield's new gypsy population is the standard liberal reaction to fraught relationships with the Roma.
When prejudices are based on nonsense they are easy enough to erode but the problem is that many of the prejudices about the Roma are not based on misinformation but come from people noticing patterns that exist. This doesn't mean that discrimination against blameless individuals is wrong but the existence of cultural traits that are destructive and unpleasant to the majority population. These include Romany attitudes to things like stealing from outsiders and violence. This article- by an almost cluelessly right on liberal offers many examples:
The following day, while chatting with a group of Gypsies in the small Transylvanian village of Dealu Frumos, I get an insight into a side of the Roma that I have been constantly warned about but have not yet encountered. A young man and his friends are telling me about tsigani de casatsi—house Gypsies—"bad ones, who don't work on the land like us but just steal for a living." Without warning, he wrenches my notebook from my hands and shoves me against the car. I am punched in the kidneys, and my arm is twisted behind me. A blade is held to the side of my neck, and suddenly I am surrounded by roaring Gypsies, maybe 30 of them, more appearing every few seconds from the surrounding houses. My translator, Mihai, is punched in the head. "Money! Money! Money!" his tormentors bellow. I am allowed into the car to retrieve my bag, but Mihai is kept outside, a hostage to my ransom. I offer all the money from my wallet, and Mihai pulls free and throws himself into the back seat. As we drive off, we do an inventory of our injuries. Apart from bruises and shock, my main injury is to my hitherto benign image of the Roma as a wronged and misunderstood people.That reporter went to Eastern Europe had clearly intended to write an article about how gypsies are persecuted by bigoted Slovakians and Romanians- but when behaviour like that is widespread in a community then someone who refused to prejudge Roma might be admirable but would also put themselves at unnecessary danger.
In other words the only way prejudice against the group will stop is if there is a clamp down on anti-social behaviour within the group.