What is Douglass argument about escaped slaves recounting their methods of escape, and what reasons does he give to support his claim?

Douglas believed that slaves had to be careful, because many people, both white and black made a living by returning escaped slaves to their owners.

At first, he could not describe his escape for fear that revealing his secret would make it difficult for other slaves to escape.

40 years later, in his autobiography "The Life and Times of Frederick Douglass: From 1817-1882", he felt free to talk about his escape.