Minor correction on copyright.
You can sue for actual damages if you have not registered. What registration permits you to do is get statutory damages, currently running at $250K per infringement. Which in the case of the vast majority of books, is way more than actual damages, hence the value of a registration.
Oh Miss Snark should have spent the weekend in the law library instead of chaperoning KY to his employment interview at Peter Luger's for a position on the "bone disposal squad".
Thanks to all the sharp eyed readers who keep Miss Snark on the unfrayed path of accuracy.