How facts backfire - Researchers discover a surprising threat to democracy: our brains
"In a series of studies in 2005 and 2006, researchers at the University of Michigan found that when misinformed people, particularly political partisans, were exposed to corrected facts in news stories, they rarely changed their minds. In fact, they often became even more strongly set in their beliefs. Facts, they found, were not curing misinformation. Like an underpowered antibiotic, facts could actually make misinformation even stronger."
http://www.boston.com/bostonglobe/ideas/articles/2010/07/11/...
The extreme cases can be found in cults where followers cling tighter to their beliefs once exposed.
A great example are the followers of Harold Camping, the Christian radio broadcaster who predicted the end of the world a few years ago, and kept re-predicting when it never came.
People's belief systems about the relative threats of terrorism and pedophiles is thus distorted by the media because the amount of time they spend watching terrorist attacks or episodes of "To Catch A Predator" is massively disproportionate to the actual level of risk posed by those kinds of things, and so especially is the emotional impact of that media.