firstly there are only five sources for these emails,  the first one we can almost certainly rule out, and that's David cameron and Number 10. you would think them being the source is something that there is a vanishingly small chance of happening. The second possibility is Rebekah herself , but according to her evidence given at the Leveson Inquiry she only has six weeks of messages and the time for that doesnt match with the content of the messages. The third  option is that the police have been leaking to the Mail, but if that was the case, you would think that the re would be much more than just the two relatively innocuous text messages. The fourth source would be the leveson inquiry itself, and if someone from there was to do the leaking you'd think that similarly to the police, firstly they would leak more, and secondly it would be a risk that might damage the inquirys process.

This leaves one possibilty as being most likely, that News International is leaking its employees emails to The Mail as part of the ongoing campaign against media regulation, a sort of  "We know what is in the rest, and we're willing to leak them, You wouldn't want your premiership to get damaged" gangster style threat.

So I know which my choice would be, but your own personal measure of who holds the lead piping in the Library may vary.

Any idiot can face a crisis - it's day to day living that wears you out.