Kookaburra sits in the old gum tree

You wouldn't believe what happened to me this afternoon. I was walking down the street whistling the tune to "Kookaburra sits in the old gum tree" and was fined $5 by the police. When I asked why they said that it is a copyrighted song and I didn't have permission to whistle it and so they fined me.

Can you believe it?