Who could tell me where this paragarph came from?

Casting a furtive glance over his shoulder, the felon slipped out of the main prison gate to be swallowed up in the British frog. A plethora escapes from supposedly secure prison embarrassed the hapless warden. To compound their problems, officials were badgered by irate citizens who accused the guards of accepting bribes from convicts whose motto was: "Stone walls do not a prison make, nor iron bars a cage."