...a couple of our bigger local stores have security devices at the doors that routinely go off for an assortment of reasons. Whether it's because the scanner doesn't work at the register or because the cashier isn't operating it properly, or because the doorway monitor isn't working, I don't know. Once I suspect it was because I had a library book with me that had been checked out properly at the library, but whose security device was not disabled by the store's system.

I do know it's a malfunction because I've been flagged, and dutifully walked back to the distant customer service, only to have my package set things off again, and get waved through by the people at customer service. I now get waved through if I merely stop and look at them. There's something to be said for being recognized, but honestly, I could rob them blind based on their procedures. It gives me a good feeling to know that they value the good will of a customer like me over the opinion of their scanner, but I wonder whether it would be different if I weren't middle-aged and obviously caucasian, and known by name by every other preschooler in the check-out line.

The result is plain, though: Both customers and employees don't pay much attention to the security monitors when they beep and flash. Unless security personnel are right there, waiting, with scanners and their own personal bodies to stop people, everyone cruises right through. The Scanner That Cried "Shoplifter".

The law must presume innocence, and merchants, if they're smart, will check people only for cause rather than accuse everyone of theft simply because they entered the building. Checking for cause will only work if merchants are deliberate and careful with their technological monitors, and consistent in their follow-up.

I find I do a lot less of my shopping at places that overtly treat everybody like thieves, anyway. Either they put their registers at the door, where they can keep an eye on everyone's comings and goings in the friendly and traditional way of shopkeepers everywhere, or I can let my fingers do my shopping on the internet. Big-box merchants probably know that, too. They may suspect that the people who have the wherewithal to avoid them are less likely to be their customers. Does that make their customers, statistically, more likely to steal from them? Almost a reinforcing behavioral loop.