I shudder to think of how people with invisible disabilities get treated. Since my RSD has gotten worse, I've always had a brace on my ankle, so the security screeners leave it alone. The brace is plastic, so I rarely set off the alarm. But if the screener started running a wand over my foot, it would be very difficult to tolerate.
Here's the article on the NYT site
And here's one that may be easier with a screen reader, or ggood if the other one doesn't work.