Just as a personal testimony on the matter, when I was 11 years old, I was watching something and felt convicted because of what I was watching. At that age I decided to not watch TV any more. I started spending more time in prayer and with God’s Word. There have been a few times through the years when I’d be at a friend’s house and look at a little news or some type of informative program, but never “entertainment” TV (not even the “clean” stuff).
I look back now at the age of 47 and I am SO thankful to God that I made that decision. Many of the other young people in my generation that I went to church with fell back into the ways of the world and are now slaves to sin; whereas, I was growing up in the same world, but without all of the EXTRA misguided confusion that TV adds, and God has kept me through the years.
Children who learn to read and to play and work outside are always much more productive in their adult years. Many psychological conditions (ADHD, ADD, etc.) have been found to be the result of too much fast-paced TV stimuli hindering the natural development of the brain in young children. I've read about studies that confirmed the connection.
It is SO MUCH simpler and more effective to do without it completely than to deal with trying to strain out what VERY LITTLE “good” might manage to make through the lines and end up on your TV set. The danger of the little bit of leaven far outweighs (in my opinion) benefit of a little bit of “good” that one may benefit from.
To me, internet is a little different, for several reasons. Great Christian individuals like Greg Gordan can broadcast VERY helpful sites that greatly benefit a person spiritually without being censored by the media laws that govern TV. Let’s hope that that freedom is not taken away any time soon!