The kids come in to the classroom after playtime, and the teacher asks...
"Hey Susan, what did you do at playtime?"
Susan: "I played in the sandbox"
Teacher: "That sounds fun. If you can write sandbox on the blackboard, I'll give you one of these freshly baked cookies"
... and points to a plateful on her desk
Needless to say, Susan writes sandbox on the board and gets herself a cookie.
Teacher: "So James, what did you do at playtime?"
James: "I was building castles with Susan in the sandbox"
Teacher: "Well, if you can write castle on the board, I'll give you a cookie"
James, being one of the brighter kids managed to work out castle and got himself a cookie and sat down again.
Teacher: "Mohammed, what did you do at playtime"
Mohammed: "Well I wanted to play with Susan and James in the sandbox, but they wouldn't let me play..."
Teacher: "Oh, well that's not nice. That sounds like blatant racial discrimination...
"If you can write blatant racial discrimination on the board, I'll give you a cookie!"