Thanks. I wasn't familiar with the ORD setup. At SEA I've seen what appears to be people using the precheck line like a line pass to the front of the elite line (which is next to it.) If you don't get 3 beeps at the precheck ID checker station they feed you into the front of the elite line. It appears to me that some people know this and get in the precheck line when they know they don't qualify. (Note: As I mention below the SEA precheck location will change soon so hopefully what I've just written won't give some people the wrong ideas.)

I wish they'd do what I've read they do at some other airports: Position someone at the entry to the precheck line and have them check whether you get the 3 beeps. Then, and only then, would they allow you to enter the precheck line. I understand that the SEA precheck line will be moving to another security checkpoint soon so I'm hoping they'll find a way to weed out those that are trying to abuse it. That would make it harder for those who are qualified for precheck but just don't get the triple beep that time but I'd be willing to accept that when it happens to me.