> I wish smartphones could be imaged and restored as easily as PCs. Imagine booting the phone from a flash drive, making an encrypted image of the phone on said drive, and writing a fresh OS before reaching the border.

Backing up and restoring an iPhone is extremely easy. You don't need to imagine all of this flash drive or encrypted imaging stuff. You plug it into your computer and do a backup. You can then wipe the phone through the menus. Restoring from the same computer is easy.