Yes-we've seen what we assumed were undercover security staff...take a look around while you are waiting...we saw guys in khakis and golf shirts who looked normal until we saw see their earpieces and the way they were scanning the crowd. They were in the bag check line as if they were waiting like the rest of us. I've only seen them once so we wondered if there was a threat that day (I'm happier not knowing). My husband spotted several more that morning...that was MK over Easter break 2014.