Conan O'Brien's Tonight Show swansong

US talkshow host Conan O'Brien has been banned from doing gags about his old bosses at NBC. The Wall Street Journal Europe reports that he told audiences during his final week as the Tonight Show frontman: "Luckily, folks, they're not saying I can't sing anything negative about the network" before breaking into an impromptu tune with the line: "Morons, incompetent morons, these people are morons ... la de de de." Jonathan Ross and the BBC take note.