I had not had any problems until my last flight out of Charleston, SC. I went through the X-ray machine and three spots showed up. One at my knee area (I have had knee replacement) one at my shoulder area and one at my head. I was pulled aside for a pat down and I just about jumped out of my skin when my crotch was not touched but actually grabed hard enough that I jumped. Nothing showed up on the X-ray to warrant being touched there. It is still a mystery why all this stuff showed up on the X-ray and I know it did because they showed it to me. I was a little upset to say the least. I've had to go through pat down since they started doing it but never experienced any thing like this before.