After a decision out of California which found that police are able to rummage through all your portable electronics incident to arrest, much attention has been focused on how much data people carry around with in their portable electronics. CNN Money is running a story with the descriptive title: Your smartphone could be your most dangerous possession.
I've brought this up a number of times in presentations about border searches, where customs agents have always had the right to go through all your stuff you're carrying but what's different now is that people are carrying around the equivalent of their personal files, their scrapbooks and their correspondence in a small package.
The threat isn't just customs agents and police, but also the fact that people lose these devices all the time. People need to be mindful of this fact and take steps to either limit what they have on their devices or take steps to make it inaccessible to others. For some useful pointers on how to do so on most smartphones, check out LifeHacker's How to Secure Your Smartphone.