So an update on this.
I found out from someone i know at TSA why so many elderly people and children are being singled out for scanning.
Apparently the agents have a percentage of, "random people," they have to send through the scanners.
If they send someone through and actually find something, it's a huge ordeal and they end up with a lot of paperwork to write.
So instead they look for the really old and the really young, who will not have anything illegal on them, and who will not try to resist of make a big deal out of the situation. I know a woman in her 80s who went on two round trips in the same year, and was singled out for special screening all 4 times she flew.