Musical profiling
I am in trouble:
Security staff at a British airport stopped a businessman from catching a flight because the songs he had asked a taxi driver to play on the car stereo made the driver suspicious, police said.
The songs: "London Calling" by The Clash, and "Immigrant Song" by Led Zeppelin, here are the offending lyrics and the story.
Addendum: Daniel Strauss Vasques points my attention to a slightly different version of the story, where the guy was just singing along.