You can write a story on the McCanns, Chris Jeffries, Jimmy Savile, Milly Dowler or whomever without sending 30 guys to camp outside their house night and day for a month, photographing them, rifling through their bins, trying to access their phone messages, using thermal imaging cameras to look inside and so on and so forth. Meanwhile everything an MP does is our business.
No laws need to be changed, just the concept of public interest. The term "interest" has been skewed to mean "what we want to read about" not "things we have a stake in" and it needs changing back. I don't have a stake in Siena Miller's tits and unless she chooses to get them out for a magazine, it's not "in the public interest" to publish them. But if a politician uses his position to get boys to fellate him, it certainly is.