Recently, my 12-year-old son and I entered the subway station at 96th Street and Broadway. On our way to the downtown platform, we saw a young teen boy being frisked and questioned by police. The young man was either light-skinned black or Latino, and he was dressed in the style fashionable for kids his age -- low-waisted skinny jeans, belted across his hips, a t-shirt, and a fitted baseball cap sitting atop his curly Afro. As we walked past, my son leaned into me and said in a half-whisper, "I wonder what that kid did." Sometimes, we mothers manufacture teachable moments. We take them to see...