The officers at my agency were sent to a class a while back to learn about these and how to spot them if not installed. Like others said, it's a real thing.
It just makes most Glock 9mm pistols uncontrollable. This was/is a propaganda "hit piece" written to frighten the general public (read "sheeple") about a "possible" threat to public safety. They're not useful in untrained hands. It takes a lot of work (and costly ammo) to learn how to employ this device effectively.Article sounds like propaganda and showing an abused or poorly cobbled together gun. Standard anti-gun statist act.
Bump stocks, slide fire devices, coat-hanger f/a fire control mechanisms,, etc.
While it might be fun to rip through a large magazine on something like a Glock 18, most of us know this doesn't make the gun any more 'deadly' and just results in more inaccurate spraying of fire. Usually with an unskilled operator spraying that fire into the mostly empty space that exists pretty much everywhere.
While I think everyone enjoys some F/A fire at some point in their life (the F-15 cannon was around 4200 rounds per minute), I can't imagine a use for something like this in a Glock amongst people who actually shoot pistols and use them as tools. Perhaps SOMEONE SOMEWHERE does, but I think this is just one of those sensational propaganda pieces to make folks think that some folks are running amok with homemade machine guns.