Why do people get hostile when they are showed a video of themselves moving items to the bag without scanning the item? Why not just accept your fate at this point and pay or give the goods back?
This leads me to think about how Walmart's focus on cheap low quality goods with stores placed in areas where finances are often tight has created this "I want it but can't afford it" despair.
You walk into this soul-less, hyper efficient box store and it's easy to notice they have a lot of stuff but not a lot of staff. And the staff are not exactly motivated to care about theft.
It's not a long shot to start to think it would be easy to get away with grabbing something, because perhaps Walmart is an easy target. But the efficiency of the place is where that mistake falls short.
The truth is, there are very few businesses with as sophisticated an anti-theft system. Walmart is dealing with petty theft on a global scale and understands exactly how much it costs them, especially if they are perceived as an easy target.
Walmart has the technology to wait until the number of thefts from a single person exceeds the local felony levels and only then press charges. It's a trap, and ripping off Walmart is a lot less profitable than it might seem.