Kudos to engine for posting this. Copyright and fair use has often discussed here and there is a lot of concerns, some valid, but many not.
I highly recommend this copyright discussion. It's long and the format is awkward. Watch it while you're having lunch at your desk. I suspect, like me, you'll bookmark it.
I like how they go beyond copyright and reach into doing what is right and ethical, about giving credit for creative works. It's the mark of being professional, copyrighted or not.