I have a Boston Bruins T-shirt
Although I only got it because it was made in Canada, and they're an original 6 team. I felt pretty awkward one time when I was at a restaurant during the playoffs last year and the manager came up to me because I was wearing it and started talking about the team to me. I had to tell him I just got it because it was made in Canada and he looked kind of upset but still took it jokingly. Fortunately they had already brought me my food otherwise I might have been worried.
I had a friend who was a Buffalo Sabers fan, and he would actually be refused service when going out to bars during the games because he had a Buffalo Sabers Visa.