I would be very surprised if it is that high now even with the early adopter skew. Reports say that last year it was around a quarter of smartphone users use passcode locks on their work phone (http://www.welivesecurity.com/2012/02/28/sizing-up-the-byod-...). I imagine 5S rates are higher than that, but 90% would be insanely impressive. When it comes to computer security, as usual, people's apathy is the biggest problem.