Like most extraordinary tales of the early emperors, this one comes from Suetonius: "Furthermore, he gave orders that one hundred and twenty of them should be hunted up and punished, having found petitions which they had written to Otho, asking for a reward for services rendered in connection with Galba's murder."

Does that mean it happened? Eh. Suetonius could be considered the first "pop historian." He wrote good stories, but his accuracy didn't always take precedence over entertainment. I can't deny, though, that the 69 AD would make a great TV series.