That friendly flight attendant who greets you as you board a plane aren't just being friendly. They're sizing you up to find individuals that they think can assist in cases of emergency.
One flight attendant says "When you’re walking on the airplane and you see our happy, smiley face, we’re actually looking you up and down and we are trying to find our ABS and what that is called is our Able-Bodied People, or person. So this is people who are going to help us in an emergency."
But, there's one more thing to this story. "We’re looking for human trafficking," she says. "It happens a lot in the industry and our passengers’ safety is our number one priority, so we’re just looking for things that look off."