Fasting from something that is good and nutritious or even unhealthy but sustaining can be a good thing, but living on a diet of poison is deadly.
Much of media today crosses the line of unhealthy into the realm of spiritual poison. Don't compromise. Be sure and get rid of anything in your possession that dishonors God.
Sometimes spiritual growth requires desperate measures. This is not a new teaching, Jesus said, "If your eye causes you to sin, pluck it out and cast it from you. It is better for you to enter into life with one eye, rather than having two eyes, to be cast into hell fire." Matthew 18:9
If you are a parent then you know how important it is to keep toxic chemicals out of the reach of small children. Yet, how often have parents allowed toxic media in the home that is poisoning the hearts and minds of their children? The following quote is from the late preacher A.W. Tozer. It is on the subject of books but what he is teaching would readily apply to electronic media as well.
"Tolerance of noxious literature is not a mark of intellectual size, it may be a mark of a secret sympathy with evil. Every book should stand or fall on its merit, altogether apart from the reputation of its author. The fact that a nasty and suggestive book was written by an accepted writer does not make it the less harmful. Christians should judge a book by its purity, not by the reputation of its author. The desire to appear broad minded is one not easy to overcome, for it is rooted in our ego and is simply a none too subtle form of pride. In the name of broadmindedness many a christian home has been opened to literature that sprang not from a broad mind but from a mind little and dirty and polluted with evil. We require our children to wipe their feet before entering the house. Dare we demand less of the literature that comes into our home?"~ A.W. Tozer
Consider some of these verses from Scripture as well.
"Therefore say to the house of Israel, 'Thus says the Lord God, repent and turn away from your idols and turn your faces away from all your abominations." Ezekiel 14:6
"I said to them, 'Cast away, each of you, the detestable things of his eyes, and do not defile yourselves with the idols of Egypt; I am the Lord you God." Ezekiel 20:7
"They will no longer defile themselves with their idols, or with their detestable things, or with any of their transgressions; but I will deliver them from all their dwelling places in which they have sinned, and will cleanse them. And they will be My people, and I will be their God." Ezekiel 37:23
You may be wondering to yourself, "what exactly qualifies as toxic media?" There are somethings which I hope would be obvious like pornography or video games like Grand Theft Auto, but other things may not seem as clear. First, ask the Holy Spirit to shed light on your media choices. Keep the subject in prayer and let your heart be open to His conviction and guidance. Secondly, think about Jesus being a guest in your home for several weeks. What would you be nervous about Him discovering? We know that He knows all these things already but sometimes it helps to play a scenario in your mind like that. Ask the question "What wouldn't Jesus Do?" and make sure you are well enough acquainted with His life and character to have a better idea how to answer the question.
There's much more that could be said on this subject but let me conclude by sharing this simple statement. We can't be too careful but we are often too careless.