The mass media is the main channel of how we know and think we know about what is going on in this world. Some of the times the information is correct and sometimes it is incorrect. It is up to us to decide what we want to believe and to filter how we come to our conclusions. Since the television networks are own by corporations the news they present is very biased towards their political views. But can you blame them? They are just trying to express their thoughts and their opinions. If I owned a television network you can sure bet I would do whatever possible to express my views.
It is up to the individual to make their own assumptions and standings on what is going on. You can't just blame the mass media for all the problems, we do need to take on some of the responsibility and educate ourselves and our children to be able to filter what we see and hear.
When it comes to the TV that our children are watching, I know it isn't always possible, but the parents do need to monitor what they want and don't want their children viewing.
My father when I was going was very strict on what we could and couldn't watch. I wasn't allowed to watch MTV with my father in the room until I 16.