Remember the story of the turtle and the rattlesnake? The snake talked the turtle into ferrying him across a river despite the turtle’s well-founded misgivings about the very nature of the snake. “You’ll bite me,” the turtle said, but the snake, able to lie convincingly to its prey, convinced the turtle otherwise. As soon as the rattlesnake slithered onto the opposite bank, he turned and bit the turtle.
“But you said you wouldn’t bite me!” exclaimed the turtle in surprised agony.
“You knew I was a rattlesnake when you agreed to give me a ride,” hissed the snake.