People born after 2000 have never seen the cosmic microwave background on their TV set.

I bought a plasma in 2009 that would show static if I turned it to cable channels without cable plugged in. Plasmas were susceptible to burn in and since I would game a lot I could see health bars etc start to burn in after a while. Whenever that would happen I would turn it to the static screen - making each pixel flip from one end of the spectrum to the other rapidly like that would actually help remove the burn in.