I've been spending the last eight months watching my younger sister turn into a Tumblob SJW, slowly but surely. She's a college freshman with a high opinion of herself and very little real-world experience, which will take you most of the way, but since we're mixed race, she falls more easily into the Tumblrite brand of white hate.
During the Grammys, she was actively rooting for Iggy Azalea to lose because "she's Austrailan, but she appropriates the way black people talk when she sings", but she had zero problem with Eminem winning. She also deliberately misinterprets things our parents say in an effort to start ranting about {insert cause here}, and it's getting to the point where I want to tell her to shut up, even if I agree with her.
I honest to god told her if she ever turns into the kind of person who thinks eating sushi is cultural appropriation, I'd stop talking to her. She promised she'd never go that crazy, but it's getting exhausting just to talk to her.