I believe the files were originally leaked to the Süddeutsche Zeitung, a centre-left German newspaper, starting last year. I remember reading some of them at the time, but didn't take much notice of them. They were mainly about corruption in third world countries and Russia, which was common knowledge. I had no idea that there would be so many files nor that so many people would be named. You're right, POGS, Cameron is a very small player. It seems that by concentrating on him in the UK, we're losing sight of the bigger picture.
There was so much data that the SDZ asked the ICIJ to help analyse the data. I think the BBC, Guardian and Sunday Times are the only UK members of the ICIJ. Presumably they're co-ordinating how and when the information is released. It seems that other newspapers and media sources are picking up on this third hand and coming to their own conclusions.
I agree with you, POGS. It would be interesting to know who hacked/leaked the information in the first place. As ever, there's almost always an agenda with leaks and it would add to the bigger picture, if it were known what the hacker(s)/leaker(s) hoped to achieve. Is it really somebody interested in global corruption? Is it somebody who wants to 'have a go' at individuals? Or is it some spotty computer nerd, who did it just because (s)he could? It would also be interesting to know why the bulk of the information is being released now. The SDZ has had these files for over a year.