In “Preaching as Worship: Meditations on Expository Exultation” (Trinity Journal 16 [1995]: 29–45), Piper ends with six pointed applications, including this one (p. 44):

2. Turn off the television.

It is not necessary for relevance. And it is a deadly place to rest the mind. Its pervasive banality, sexual innuendo, and God-ignoring values have no ennobling effects on the preacher’s soul. It kills the spirit. It drives God away. It quenches prayer. It blanks out the Bible. It cheapens the soul. It destroys spiritual power. It defiles almost everything. I have taught and preached for twenty years now and never owned a television. It is unnecessary for most of you, and it is spiritually deadly for all of you.