Phone hacking

I watch the phone hacking scandal with disbelief. I can understand how average joe gets hacked, especially with regard to answerphones: the pin is four digits, and though it may take some time, this is guessable (why isn't a text sent whenever there is an incorrect pin entry, with 5 wrong guesses causing a lockout for two hours?) What befuddles me most of all is that Gordon Brown is concerned about phone hacking:

  1. If the PM (for he was once) is using a mobile, and worried about interception of signal, why isn't it encrypted by default?
  2. If the PM is worried about the voicemail being hacked, then why is the default orange voicemail being used (or vodafone, or O2 or whatever) - have they checked the security? Are they sure no rogue telecom employees can listen?
  3. Most importantly, why on earth is there an automated system for voicemail at all? The phone isn't answered because the PM is busy (a real possibility, surely) - but the phone call might be important (also a real possibility). In that case, forward the phone call to PMs private secretary who will take the message in a more secure way. If the phone is the PMs private number, then this can still be done by a professional and discrete secretarial service.

The focus of the 'phone hacking' story is all wrong. Right now, it shouldn't be on 'Did the News of the World' indulge in hacking the PMs phone?' - but it should be 'Why are our communications so weak that there is even the risk that a tabloid journo could hack the communications of the Prime Minister?'

None of this is to diminish the naughtiness of hacking into the phones of other individuals, and that investigation should run its course; but right now, I'm mostly wondering 'Why was the PMs phone so insecure?' and 'Could this apply to the current PM?'