It happens to me all the time because I look middle-eastern when I'm really hispanic. I was working at a coffee shop and two hispanic men came in talking smack about our food and confused about the menu. Right in front of me the guy's like "Lets ask this guy" "This guy? What's this camel gonna know about anything here" (I guess camel is a slur for middle eastern or something?) I responded in Spanish and it was back-pedal o'clock.