A big part of the problem, at least here in the US, is that the media acts as a propaganda arm of the government and corporate interests that benefit from the dehumanization of groups of people. People here are being constantly bombarded by subtle, but definitely negative and highly distorted (and oftentimes, outright false) messages about certain groups of people. As long as this kind of thing is going on, it will be very easy for these interests to manipulate the perceptions and attitudes of the majority of people in this country when it serves their purpose to do so.