Be careful, comrade, you when let everyone know all is OK. Or when you stretch your hand. Or flash your winnings. Because you are signaling (if you’re reading this aloud to someone, do so in a whisper) — you are signaling white supremacy. Yes, you. White. Supremacy. How, you ask? It happens when you touch your forefinger to your thumb to make what is commonly known as the “OK” sign. That’s what a 17-year-old Hamilton, Ontario, girl reportedly did in a picture she posted on social media when she was excited to get a high school co-op position at Juravinski...