Interesting in this context is completely divorced from morally good/bad. Could be any group from any area at any time in history. I’ll start with a few, followers of the cult of pythagoras, contemporary black Hebrew Israelites, antiracist skinheads and the Amish (neo-luddites in general). Don’t be racist or a prick to other people discussing.
Early internet was weird. I found a forum where gay men would write public, erotic love letters detailing their willingness to contract, or transmit HIV to each other on purpose. Like, viscerally describing giving or getting each other’s “pozzie” (HIV-positive status)
Yikes! I think I’d rather be a gainer.