Margaret Sanger was a thoroughly evil human. She was a champion of negative eugenics, the belief that less "fit" races, like blacks, hispanics and Asians, should have their breeding limited through mandatory birth control, abortion and forced sterilization. She started a pro-birth control organization that was the predecessor of Planned Parenthood.
Although much of the radical feminist movement considers her a hero, the truth is she was evil, and her evil influence continues on through Planned Parenthood. I just found this audio of someone prank calling Planned Parenthood offices, and saying horribly racist things to see how the PP people would react.
Watch it, but let me warn you: you're likely to get really angry, and a little sick. Also, the subject isn't really kid-friendly, so be warned...
By the way, if you're wondering, PP is funded by your tax dollars. I'm sure you are as happy about that as I am.