No, but I had one sit next to me on a flight to Vegas once. It's a long story, first how we suspected and then when he admitted it as we got off the plane. They do exist though.
Once we got in the terminal he kinda flashed his ankle holster and told us to have fun on our vacation. Also mentioned something along the lines that we had made a normally boring 5 hour flight entertaining.
I should add this was 10+ years ago.