http://en.wikipedia.org/wiki/LGBT_symbols

On Halloween night (31 October), 1969, sixty members of the Gay Liberation Front (GLF) and the Society for Individual Rights (SIR) staged a protest at San Francisco's Examiner in response to another in a series of news articles disparaging LGBT people in San Francisco's gay bars and clubs.<1><2> The "peaceful protest" against the "homophobic editorial policies" of the San Francisco Examiner turned "tumultuous" and was called "Friday of the Purple Hand" and "Bloody Friday of the Purple Hand".<3><4><5><6><2> Examiner employees "dumped a bag of printers' ink from the third story window of the newspaper building onto the crowd".

I narrowly escaped spending time in jail that day, I was lucky there were a lot of leaders that day, more willing to step up to the SFPD than I.

http://en.wikipedia.org/wiki/LGBT_symbols#...