Another vote for displaying scars not being effective. A couple years ago I wore a dress on a trip. My artificial ankle joint set off the beeper, so got pulled aside for the pat-down. Took off my shoes to be wanded head to foot. The long scar on the front of my ankle was pretty obvious, but when the wand beeped at my foot, the TSO still ran her hand over my foot and ankle. As if I was hiding a weapon *INSIDE* my foot? ...?

Anyway, it was too ridiculous not to laugh but I managed to hold in the laughter until I was away from the checkpoint.