Banksy Tags The Simpsons

Street artist Banksy took it to the 20th Century Fox studios for an October episode of The Simpsons, where he was given the opportunity to storyboard and direct the intro. My thought: how did he get away with this? More importantly, why did they let him do this? Honestly, I found it mildly offensive, that whole portrayal of child and factory labor and all.

Thoughts?
-E