A lot of common security measures can be defeated with modest technical skill and diligence. Fortunately for the police and the public, the vast majority of armed criminals are not even modestly technically skilled and diligent. They're largely fools with poor impulse control. If you are smart enough to spot weaknesses in security measures and implement workarounds, you probably already have a job with better long term prospects than "bank stickup guy."

There are some criminals that get rich from armed robbery, but your typical armed bank robber has a short and none-too-lucrative career:

http://www.businessinsider.com/people-are-robbing-banks-in-r...

https://www.thestar.com/news/insight/2013/04/26/bank_robbers...

https://www.theguardian.com/commentisfree/2014/jul/04/where-...

> A lot of common security measures can be defeated with modest technical skill and diligence. Fortunately for the police and the public, the vast majority of armed criminals are not even modestly technically skilled and diligent.

Yes - although almost none of them have the technical expertise to manufacture a gun and yet significant number of criminals own them. Similarly criminals don't need the expertise to own a "gun obfuscating device" to own one.

There's a large, legal market for firearms in the US, so it's not hard for a criminal to take advantage of that. What's going to produce a large, legal market for dedicated gun obfuscating devices that criminals can similarly take advantage of? I don't think that there is going to be one. I think it will be more like a criminal getting access to e.g. plastic explosives: either he's part of a criminal organization, already has a specialized day job that allows for diversion, or has reasonably high technical skill and can manufacture the materials in a home workshop. I'm not sure the "diversion from legitimate business" path even works here, because again, I don't see the business need for disguising open carried guns. If Johnny Hothead, having no specialized connections, gets an offer to sell him some explosives then it's probably coming from an agent of law enforcement rather than the local Crime Depot.

simply shroud your firearm in a piece of cloth like the hitmen in gangster movies.

Or a piece of paper?