I believe that the media and Governments often blame cultural intake for people's actions for a number of reasons, none of which hold weight with me. One irony is when the media talk about 'the media' it is an exclusive term that they don't include themselves in, this only weakens the logic of the argument.
Behind most crimes and anti-social behavior blamed on media lies a multitude of social and economic issues that are far harder to put right if they are acknowledged as a part of the problem. It is easier to cite Marilyn Manson as the reason for Columbine than to question parental responsibility, school discipline or laws that surround gun ownership let alone the culture and celebration that surrounds gun ownership.
Art imitates life, it is a mirror held up to the world, the irony is of course that it is a self perpetuation as art becomes culture and has an impact.
One point of interest, Manson said Helter Skelter by The Beatles was a message about race war, the Bulgar killing was blamed on the film Child's Play 3, The Night Prowler listened to ACDC and Judas Priest were blamed for inciting kids to kill themselves...all these case were honestly considered to have been genuine influences on those that commited crimes.
More than any other text The Bible is cited by killers, serial murderers and rapists as an influence over any other cultural artifact in existance - when people say God told them to do it they are labeled as fantasist. That is hypocrisy.