My husband and I could both be considered "elderly", though we are frequent flyers (AA Platinum) and Flyer Talk readers--so we can't be said to be clueless travelers. I have never been singled out, and neither had my husband until he had a knee replacement. Now he gets the full pat-down and security going over every time. With joint replacement becoming more commonplace, I wouldn't be surprised if that's the main reason for singling out the elderly for added security checks. Too bad there's not some sort of joint replacement ID card that could be issued by hospitals so that all this security could be avoided.