Yes, that's from Suetonius' account on Caligula: He often inveighed against all the senators alike, as adherents of Sejanus and informers against his mother and brothers, producing the documents which he pretended to have burned,54 and upholding the cruelty of Tiberius as forced upon him, since he could not but believe so many accusers. He constantly tongue-lashed the equestrian order as devotees of the stage and the arena. Angered at the rabble for applauding a faction which he opposed, he cried: "I wish the Roman people had but a single neck," The context is quite appropriate.