Originally Posted by Bart

The most common mistake travelers often make is placing disks or the miniature removable hard drives in their pockets as they enter the WTMD because they want to avoid having them x-rayed. Even when the WTMD alarms, there's a chance that the disks aren't damaged. However, during secondary screening, when the hand wand is held right up against the pocket where the disk is, the double-zap from the WTMD and hand wand pretty much affects whatever data was stored in the disk/drive.