There has been more written on this hack by David Kearn (a known propeller-head in identity management) in his blog Virtual Quill. Read what he has to say if you are interested.
Bring Your Own Identity (BYOI) is on the band-wagen with BOYD (Bring Your Own Device). Wired journalist relays a sobering story of how his digital identity got stolen through trusting third-party identity providers.
Basically Hackers were able to swipe his mac, iPhone and hack into his twitter account to send twitters that were damaging to Mat Honan’s reputation. He was using iCloud, the hackers hacked into his iCloud account, and they got in because Apple uses the last 4 digits of his credit card as a form of authentication. They got the last 4 digits that are incidentally stored as clear-text by Amazon through a bit of social engineering. Know I bet you want to read the whole story? Read more here.