About ten or fifteen years ago, I was getting QSL's for a while from ops who had "worked" me on 6 meters. Only problem was, at that point in time, I had no 6M gear and had never been on 6M. I returned the cards with a brief note apologizing for the disappointment.
I always wondered if someone was bootlegging my call or if it was a misunderstanding by the ops who QSL'ed me.
Six meters seems to be rife with this kind of thing. I haven't had any operational gear for 6 meters since the late 60's. But, I still get a card now and then claiming a contact on 6 meters. However, I never thought that someone was bootlegging my call. My guess is that it was simply the product of a less than stellar contact. Most often they mistake the beginning "W" for a "K". Of course, it doesn't help that W7MEM's first name is Mark.
Martin - K7MEM