Chiefs fans, Bengals fans, Jets fans, Packers fans, maybe some other teams I have missed. There have been a few guys over the years, but most of them didn't stay long.
I've always thought Spags is someone from this board pretending to be a Jets fan. It's still been pretty funny over the years.
I think Zerovoltz has made it the longest as someone posting on our board as another team's fan.
I never understood it, joining another team's forum. I will go read them after a Bills win at times. But I don't interact with them, nor do I feel the need to do so. Some of your own favorite team's fans are insufferable enough. I can't imagine being as petty as to troll them in that manner.