It happens more on Express flights, and far more on CO than UA (since they have fewer aircraft equipped with music, I think). I've been lectured about the necessity of hearing announcements in an emergency. Other times they are looking for ways to be fussy and to assert their utter transcendance in their lofty domain.

I'm always prepared now. I turn the red light so it can't be seen and set the plug-in jack on my knee where it can obviously be seen as something that is disconnected. This is important, because once they swoop in to arrest you for having your CD player on, they won't easily concede that they wrongfully thought you were listening to music. Then they'll make up FAA regulations on the spot, declaring that you have to have your ears uncovered and all devices of any sort turned off. (What about hearing aids and other items such as that?!)

This is really the issue, which is why I cannot stand being told this kind of nonsense. Few things enrage me more. While going through graduate school long ago, I was a flight attendant. I think that's why nothing burns me more than to be told to do something by a flight attendant when I know that they are deriving their life's meaning from bossing passengers around. I wish I could laugh, but it burns me up.