I will give Google/YouTube the benefit of doubt (at least for now) that this is due to some third party, in this case likely Modern Language Association, an Anti-Israel group, claiming alleged copyright infringement. Groups like MLA do this to quash speech and hurt their critics. But it is disturbing. If they can successfully do this to Legal Insurrection, who is next?
Instapundit: Censorship: YouTube shuts down Legal Insurrection's Account
Wombat: DaTechGuy: YouTube shuts down LI's Channel and Back up
Victory Girls: YouTube yanks Legal Insurrection's Channel
Update: It is back up, but legal battles are still to be fought and as DaTechGuy cautions, expect more of this. Push back hard when it happens. And as Glenn Reynolds notes: Stand up for Professor Jacobson and Legal Insurrection