This Sunday, one of the readings in church will be the story of David and Bathsheba. David is a powerful king, who gets what he wants. He wants Bathsheba, who is married to another man. To cut a long story short, he has her husband killed so that he can marry her himself.
There is a prophet called Nathan. Nathan confronts David with what he has done - he 'speaks truth to power'. Powerful as he is, David could have Nathan silenced; but Nathan speaks so skilfully that David becomes ashamed of himself. He confesses his sin to God, and Nathan leaves unharmed.
Over the last week or so I've been following the story of Edward Snowden. He's the guy who has 'blown the whistle' on America's security services. He says that they are monitoring internet use to a degree not previously imagined by most people.
There's been quite a response. Some parts of the American government deny that anything illegal has happened, and seem set on punishing Snowden for damaging their efforts to stop terrorism. Others seem to think he has done a great service in exposing illegal government activity.
I honestly don't know whether Snowden is right or wrong. But either way, he has done an immensely courageous thing - he could pay a terrible price for his actions. It isn't easy to 'speak truth to power'. And if the American government and security services represent anything ... it's power!