I've seen two, and both times it was hastily flashed in a careless moment. One guy had it in a belly holster, and he yawned and stretched (I knew that he was a cop beforehand, so I decided to not yell "He's got a gun!") and one IWB carrier that stepped out of his car on a windy day.
I've learned from both of these incidents, and they've made me more careful about how I carry. I know what to look for now, too.
------------------
-Electric Armadillo-