Good question. I wrote in to 1K last month as pretty sure it was a non rev since they were on standby business and F list and the guy got placed in a Y seat. The entire flight he was being very demanding and needy - required bottled water from the front, a business class meal, etc. I also had to listen to him complain the entire 10 hour flight on how he was screwed over for not getting a business seat yet another non rev received it. It just poorly reflected on UA. 1K just said thanks and we appreciate your loyalty and feedback and will share with management. I would have to assume they have to have a way to look into problem non revs