Most here are not old enough to remember this.

One way tickets cost as much as round trip tickets. So people would buy a round trip ticket then sell the return ticket. This was standard practice And they never used to ask for picture ID when you flew.

The requirement for picture ID was instituted on the behalf of airlines seeking to end the practice. It wasn't about security. It was about money.

Incidentally there is no actual law requiring picture ID. Well, the FAA says that it exists, but won't tell anyone what it is. (I wish I was making this up.) This was the subject of a lawsuit that was lost in the 9th circuit and not heard by the Supreme Court. See http://www.papersplease.org/gilmore/index.html for more.