[dspillett]

You might be able to argue that, though you are arguing against accepted practise (are you are wanting to ban all web crawling?).

While two wrongs don't make a right, assuming we accept that facebook is wrong in this instance which I don;t think I do, the code for the page handing out sensitive information to an unauthenticated request or taking action based on malformed inputs is negligent.

"Information wants to be free" is not just a hippie ideal it is a technical warning. Unless you take proper measures to control and protect sensitive data it will find a way out.