A Pirate Shanty

Suport your independent Mac developers. I got this message today after trying to use what appears to be a wrong serial number:

A Pirate Shanty

I'm a pirate! That I be!
I sail me ship upon the sea!
I stay up late - till half past three!
And that's a peg below me knee!

I've got no hand but that's me hook!
I pillage stuff but I'm no crook.
Me booty's in this chest I took.
They'll write about me in a book!