In the fraud/theft detection I had some experience with, everyone learns right away that mistakes happen all the time. Singular incidents are basically not worth investigating unless something about them is highly unusual, like an unusually large dollar amount or aligning with a scam that has become popular.

When I watched movies and TV shows I had this idea that thieves were all clever people who built smart systems to evade detection and steal right out from under big corporations. Some of those people might be out there operating undetected, but the average thief who gets caught is someone trying to abuse something as much as they can until they get caught. Some of them are so brazen (like the scan everything as bananas post above) that they must believe that nobody will ever check and if they do get caught nothing bad will happen.

The staff who watch these things have a good sense of what dollar thresholds the customer must cross before getting law enforcement involved.

I've had awkward interactions with the Walmart system. It's clearly using a neural net, and a good one at that. It's only ever flagged me when I did something odd (like put something bagged and paid for in my cart, then take it out, then put it back again). I dress/groom like a thief, so the conversations with the staff are always annoying.

If you dress like your HN username indicates, then yeah, you're probably noticed by humans before you get into the store.

Ironically, some of the store security look exactly like you. They come in all shapes, sizes, grooming standards, styles, and tattoo levels. I've seen some in full-on Juggalo outfits and neck/face tattoos.

One of the AP (asset protection) guys at my local store always wore an eyepatch and a t-shirt reading "A bullet a day keeps the terrorists away". He did NOT look like a typical grocery store employee, and I'm sure that was intentional.

"Clothes make the man", as the idiom says. Clothes don't impugn your character, but they define you in the eyes of others.

Having been a long-haired holey jeans-wearing guy in my past, I was naively surprised when I cut my hair and noticed that people treated me very differently in business settings. When I started wearing nicer clothes on top of that, it was night and day - the kind of reception you get in banks, anything like that. It sucks that humans are built to judge and filter on appearances, but it's just the reality. You can use it to your advantage.

Honestly, I trust these systems more than humans to do the same work. While we're all talking anecdotes, this one time at Walmart (how all good stories start) many years ago I was in the music section and these two in-store security guys approached me, saying they had told me to never come back in the store, etc., making a big scene. I so rarely go to Walmart and found the situation kind of humorous and wanted to see where it would go (knowing I had not done anything wrong now or in the past). They had seen me on video evidently and thought I was somebody else - serial shoplifter or public urinator or who knows what. Anyway, I tell them I've never been told to leave prior to this visit, didn't know what they were talking about. They were adamant that I was in the wrong, asked me to come back to the office while they looked into things. I was like, "sure!", more entertained than upset. So there I am sitting in the office while some guy combs through video footage. A guy of authority comes in, tired demeanor, asks these guys - well, did you match his ID? "No", says he. Checks ID, realizes I'm not their guy. Many stressful apologies on their behalf. But that's humans for you.