The female agent who happened to be on duty knew what it was and only gave it a cursory inspection, but her male supervisor was insisting that he wasn't letting that suspicious machine on board unless she operated it in his presence first. My colleague said, "Well, if you really want to insist, OK ..." Apparently, at this point the female agent whispered to the supervisor exactly what the pump was for and how it was used, because the supervisor turned beet red and told my friend to go ahead and board!
Some people are still REALLY squeamish about BF, especially men.
BTW, when I was nursing there is no way I ever went to an airport without my pump if I didn't have the baby with me. A flight delay could get really painful.