I would just like to inform interested readers about the technological details the media seems to ignore. Now, as far as I am aware there has been no hacking but there has been tapping of telephones. This might be a battle of semantics but lets see where it gets us.
Hacking a phone is very difficult. Most of our politicians use the BlackBerry for a very specific reason: it is very impossible to hack. So difficult indeed that Indian spooks gave up and forced RIM (the makers of BlackBerry) to give them the 'keys' for the phone (i.e. the software encryption code). This should give the reader some clue as to level of intricacy involved in hacking mobile phones, and BlackBerrys in particular, used by all government and major corporations because they are deceptively hard to enter without permission.
What you need to ask yourself now is this: could a NoTW private investigator accomplish what the entire Indian secret service could not? The smart money is on 'no'. Hence we can but conclude that the media, as always when it comes to technology, got it wrong. Whenever they talk about malign computer breaches they speak of 'hackers' as well even though the correct term is 'cracker' - two very different sides of the coin.
What they with all certainty did do was not phone hacking (because they do not have the brains nor the equipment to do that - GCHQ does but they are a government funded spy department with 20,000+ employees and a billion pound+ budget). What they did do was phone tapping which Wikipedia defines as 'the monitoring of telephone and Internet conversations by a third party, often by covert means.' This is much more within the confines of their technological expertise. It is not particularly hard to do if you have the right stuff. Joe Bloggs on the street could do it with some basic instructions. And by the looks of it Joe Bloggs on the street did do the tapping, judging by the fantastic mess they have created as a result of their amateurism.