Yeah, I'm not at all convinced that it is infringing. 1. It can definitely be argued that it is for an educational use, and I can't think of any valid argument

Yeah, I'm not at all convinced that it is infringing. 1. It can definitely be argued that it is for an educational use, and I can't think of any valid argument that it is for a commercial purpose. 2. It's a user created music video, so he has a case here. 3. Warner might have a good argument here. Lessig did use about 50s of the song. 4. I really don't see Lessig's presentation as having a useful replacement for the song. Lessig starts playing a lot of copyrighted material around 9 minutes into the presentation to illustrate remixes.The Muppets song is played at about the 11.00 min mark. The presentation is about 50 minutes long, so I really doubt that his purpose was to violate copyright law or to even play a specific song.