What is going on?: Desktop vs. Mobile device security models

I was wondering if anyone can help describe or elaborate the security/privacy shift in models from desktop/laptop computing to mobile devices. I am sure everyone can "feel" this happening, but I haven't seen it explained out. Examples below where the approaches for the same tasks differ in security model: [Desktop/laptop OS] / [Mobile] ------------------------------ Unlocking — Unlocked via long password (no data destruct) / Unlocked with 4 digit pin (+data destruct) Logging in to services (e.g. Facebook, Seamless) — Desktop apps time out / Mobile apps stay logged in indefinitely Changing settings - Desktop needs an "admin" user / Mobile change settings any time Camera/recording - Camera LED on bezel / no camera LED activates on mobile device Files/storage - Desktop, can manage local storage (e.g. Explorer, Finder) / Mobile, no way to "see" data except through apps Common corporate email setup - Check mail - Deskto (1) Login/unlock laptop, (2) Login to VPN, (3) Login to Outlook / On mobile, Exchange mail credentials stored in device policy, only password required is screen unlock - Visit intranet sites — Desktop: Unlock computer, VPN, browser LDAP login / Mobile: device cert allows access Just curious if anyone can describe what is going on with computing from a perspective of trends, assumptions, and models. Thanks for any insight provided! Happy Friday musings!