San Francisco Pride monitors attempted to expel the first organized SM contingent (Soc. of Janus) in 1978, and moved to ban attendees from even wearing leather *clothing* at Pride in 1979. Lesbian S/M group group Samois successfully fought that ban.
https://aphyr.com/posts/358-a-history-of-leather-at-pride-1965-1995#san-francisco-pride-1978