[dunham]

The built-in guest account runs on a separate copy of the OS, booted from the recovery partition. It is a limited OS image that only runs Safari.

A normal account would require unlocking the disk, which would expose everything.

Last time I looked at Prey (over a year ago) it didn't support installation to the recovery partition. But they may have added support since then.

[paxswill]

If you're already relying on OS X's FDE, it's not a huge step to link your laptop with iCloud. You can then do basically all the things you can do with a lost iOS device: beep, send messages, or wipe it (instantaneously if FDE is on, it just clears the keys).