Cory Doctorow once again tries to lay out the sensible way copyright should work. Even if you don't agree with other stuff that Doctorow does, his stance on copyright should seem sensible. Unless you're a corporation like Disney or the RIAA.
Fair use, people, know what it is and when you can (and should) claim it. More importantly, stand up and defend it when its infringed upon by bullies of any size.