Today is a big event in San Francisco: from Wikipedia:
The Folsom Street Fair (FSF) is an annual BDSM and leather subculture street fair held on the last Sunday in September and caps San Francisco’s “Leather Pride Week”. The Folsom Street Fair, sometimes simply referred to as “Folsom”, takes place on Folsom Street between 7th and 12th Streets, in San Francisco’s South of Market district.
The event started in 1984 and is California’s third largest single-day, outdoor spectator event and the world’s largest leather event and showcase for BDSM products and culture.