Barry Britt said his goal in presenting on copyright in the classroom is to change the mindset of teachers to at least be thinking about copyright issues. He uses the acronym LEO: Legal, Ethical, and Ownership.
Personally, I find copyright and fair use very confusing. I've always given teachers this advice: "What happens in the classroom STAYS in the classroom," a take off on the Las Vegas slogan. Teachers and students get into trouble when they effectively begin "distributing" copyrighted materials either in printed form, or electronically on the Internet or on CD.
Barry is right when he says teachers need to begin to think about copyright. Teachers don't bother to teach their students about copyright law, ethics and ownership because it's not something they think about-- they're more focused on content, standards, classroom discipline...there's no time left to teach or even to think about copyright.
Even after students learn about "LEO", I believe they need alternatives to copyrighted media, like creative commons, or a subscription to a service like Soundzabound. That way the teacher doesn't have to be the copyright police, and students don't need to worry about obtaining permission to use copyrighted content.
Although it's 6 years old, THIS ARTICLE from techLEARNING by Hall Davidson is one of my favorites on copyright.