Also, there are other options for menstruating women who want to use the scanner and not be pat-down. Why not use a moon cup / diva cup or similar device?

Reusable (cotton washable fabric) pads are also popular with some women. I wonder how the machine would tell the difference from a cotton pad and cotton undies.

Also, could they even require you to remove a tampon or pad? I'd think those count as medical devices, similar to how glasses count. Just because only 1/2 the population needs them at some point, they're still medical. It'd be a biohazard to not use some sort of device when you're menstruating.