I've only encountered 2 pipe smokers in the wild, one when I was in my (pre) teens and one older fellow at work which quite smoking after a heart attack, he is retired now. When I smoke my pipe during my break at work or before work it is a conversation piece when people join me smoking anything else, but further more I've never seen a pipesmoker in the wild.
I don't mind the conversation when asked and answer any question they ask, but I would rather leave a fellow pipesmoker alone when they don't start the conversation.