▲ Do you know the history of the Black Triangle? ▲
Nazi's and Lesbians
..according to our good buddy Wikipedia anyways.
Here's the first paragraph of the Wikipedia page;
The black triangle was a badge used in Nazi concentration camps to mark prisoners as "asocial" or "arbeitsscheu" (work-shy). It was later adopted as a lesbian or feminist symbol of pride and solidarity, on the assumption that the Nazis included lesbians in the "asocial" category. More recently it has been adopted by UK disabled people's organisations responding to increasing press allegations that disabled benefit recipients are workshy.