Why is that a concern? Obviously you can fool the system into thinking you have a gun, but I don't think casino's will have any qualms in banning fake-guns.

Based on their description of the tech, you can trigger the system with something that doesn't look anything like a fake gun. It just has to have similar resonances.

The article mentions machine learning. So, it triggers, they search you, they find a thing that is not a weapon, they update their database and comp you something for disturbing you.

Of course, they could as tgb suggests just ban anything that triggers their limited tests but that would impact income once word got around

But until that happens, a casino is consistently getting false negatives. What happens when the trinket for sale as you're exiting Cirque du Soleil looks like a machine gun to the system? Suddenly, you've got dozens of people held up at the entrance. At best, that's a customer service annoyance; at worst, a bad actor could use this to their advantage.

Then they put a sign up saying "please remove trinket from pocket". This really doesn't seem like a huge problem.

Sure it does. Who's going to go because they constantly get stopped?

I think the false-negatives of such a system, which weren't entirely addressed ("will get better with machine learning"), would be worth more to look into than things not guns being seen as guns.

False negative and false positive rates are correlated, you can generally trade off one for the other - although I don't know how easy that is with machine learning. The false negative rate doesn't have to be perfect to be a deterrent - would you try to sneak a gun into a casino if you knew you had a 50/50 chance of being caught?

People sneak and accidentally take guns on a plane all the time and don't get caught, but I'm not sure what the 'catch-rate' is for that.

Well, that's a concern (for the profitability of the casino) but isn't what I was replying to. The parent post was suggesting that there could be objects designed to look like guns to this system. I have a hard time imagining why anyone would do that.

Which implies it shouldn't be too hard to sneak in a gun if it doesn't look like a gun to the scanner.

I'm far from an expert, but my understanding was that those kinds of adversarial attacks would be prohibitively difficult without full access to the learning system used by that product. If so, there's a vector if you can hack the company and train your own model to generate the adversarial examples to fool it, but it's not a trivial thing

I think the so-called carousel attack would apply.

Assuming the penalties for bringing in a gun are low, "oops, I forget, sorry," all you need to do is send in a train of people with different types of attacks and note which make it through.

> Assuming the penalties for bringing in a gun are low

A quick check (ETA: of Nevada law) shows that "gunbuster" signs don't have force of law. Assuming you leave if and when asked, there's absolutely no legal repercussion to ignoring them.

This varies from jurisdiction to jurisdiction. It's a crime in Texas for a licensed concealed carrier to carry a gun onto property where there are signs prohibiting the carry of guns.

http://codes.findlaw.com/tx/penal-code/penal-sect-30-06.html

Of course - I should have specified, I checked Nevada law.

That said, Texas law requires very, very specific signage. The last time I was in Austin I saw lots of them, but none that met the legal requirements.

> That said, Texas law requires very, very specific signage.

Exactly right. The amateur signs you see are almost a running joke, to intimidate new CCW permit holders. Here's the full description of what standards a sign must meet to be enforceable: https://en.wikipedia.org/wiki/Gun_laws_in_Texas#30.06_signag...

Bonus, you can carry without a permit, as long as you claim you were 'travelling', and the burden of proof is on the cops to dispute it: http://www.dallasobserver.com/news/texas-concealed-gun-laws-... (this law may have changed by now, but it was widely known when I lived there).

It's the same in Ohio. Most buildings that ban guns don't have the proper signage.