The original version is quite different from the version performed today. The original lyrics refer to the pun of "radioactivity" versus "radio activity", meaning, activity on the radio.

The new live version refers almost exclusively to the former meaning, and adds "stop" to turn it into a protest song.

I've seen Kraftwerk live twice, at London's Albert Hall and Berkeley's Greek Theater, both times absolutely amazing. Highly recommended.

I've often thought they would be the ideal band to perform inside the "Sphere" in Las Vegas.