airport security

I thought I was being so cool when I used a picture of William Burroughs sitting on a porch holding a rifle as the desktop background on my linux machine. I don't use linux for presentations, so I thought I would be safe. However, it didn't seem such a good idea when I was going through security at an airport and security asked me to turn the laptop on. As I watched the screen come up at the airport, I suddenly thought this could all end in tears (or me missing the flight). Anyway the security guard was not watching the screen. I have a picture of a bluegene computer on the windows partition.