It’s true. The Greek author, Plutarch of Chaeronea wrote several biographies and one of those was about Julius Caesar. When he was a young man, he was captured by Cilician pirates, who held him captive for about thirty-eight days. He was held on the Mediterranean Sea and the pirates first demanded twenty
talents. He burst out laughing and told them that they did not know who they had captured and offered that he was worth fifty talents, instead. He even sent the two servants, who were there to guard him up to the violent pirates to tell them to stop talking because he wanted to sleep.
Julius Caesar did not behave like a normal captive and in fact, kept the attitude that they should fear him and do what he said. They merely laughed it off.
He even joined them in their games and exercises, as if he was their leader. Writing poems and speeches, he read them aloud to the pirates and if htey did not admire his writings, he called them “illiterate savages” to their faces, while threatening to hang them after he was freed. They took this behavior as a boyish playfulness. They should have taken him more seriously.
As soon as the ransom arrived from Miletus, he paid it and was freed, going immediately to Miletus to man some ships and find the pirates. He found them in the same location and captured almost all of them. He took their property and put them in prison at Pergamon. He, himself went to the governor of Asia, Junius, who was taking his time deciding what to do with the pirates. Junius, however, was lusting for the money, which evidently, was a large amount.
Caesar did not feel like waiting and travelled back to Pergamon to deal with the pirates, himself. He had them brought forth and crucified. When he was being held captive, he often threatened to have them crucified, to which they thought he was joking. I guess they found out he was not. Caesar was merciful to them by having their throats slit before they were crucified.