They do the same thing with strollers, stuffing goods inside them. I have a friend who maintains a small booth at an antiques mall - they finally had to ban strollers and add more cameras due to rampant shoplifting, but still they will steal anything not nailed down. She has to be incredibly picky with what’s in her booth - it can’t be anything small of value or it would have to be in a locked case and cost more overhead to sell.
My wife had the two kids in the stroller and was with out-of-town visitors. Went up in the tall building that overlooks the city to take in the view and browsed the gift store.
They go back down the elevator, across the park to the parking lot to the car. She lifts the first kid out of the stroller, and stuffed behind her back are all sorts of trinkets! The second child (I’m guessing they were 18 months or so, twins) had a stash too!
So my wife left the kids with the relatives at the car and had to schlep all the way back up there, hoping that they wouldn’t accuse her of shoplifting!