One of the less obvious trends of the last five years has been the race to own people's "digital identities". It started in earnest with Facebook and Gmail and it soon spread to Apple and LinkedIn. More recently, we've seen Microsoft and IBM jumping on the bandwagon and I think that's when I started to realise that there was much more to this than simply "targeted advertising". Quiet Beginnings At this point, I'm not sure that all of the founding companies in this revolution fully understand what is going on - and indeed, there are many companies out there today who are still using digital identities simply as a means of easily logging people onto their systems, storing user preferences and targeting advertising. Certainly that was the original plan on our own systems. Taking it to the next level Digital identity is the cornerstone in any form of electronic ledger system. It's one of the key foundations of commerce. People don...