The best example I remember is the "piss hardon" discourse that lasted for about five years of consecutive issues in MaximumRockNRoll. N.b.: it was not a band, but the mystery of morning wood.
USENET and Listservs were much closer to the dynamic of articles & LoCs of old-school fanzines than any sort of social media.
And the nearest thing to APA culture? Tumblr.