Perhaps you ought to calm down, before going into 'outrage mode'. Unless you'd like them to fine him without bothering to investigate first:
http://www.bbc.co.uk/news/uk-politics-15396956
He is, in fact, being investigated by the ICO. Ignore the headline on that article by the way. He's been 'cleared', only in the sense that the Cabinet Secretary has asked him if he'd done anything naughty, and he gave assurances that he hadn't...
However if the Mirror had found anything damning, they'd have told us - as I'm sure they'd have been very pleased with a juicy resignation. So we can probably assume that nothing more than a slapped wrist is coming his way.
I just think that we should give people like the ICO a chance to actually make a cock-up before we accuse them of it. You never know, they might actually get it right...