On January 13 of this year, ATF issued the final rule to take effect on January 31, reclassifying the pistol/stabilizing brace as a stock. It is estimated that by May 31 after a 120 days grace period, between 0.6% to 8% of all pistol braced firearms (255k applications) were registered as short-barreled rifles, turning the rest into felony violations if not reconfigured back as pistol (remove the brace) or rifle (permanently lengthen the barrel). Many customers could very well have walked into a gun shop and never noticed they became felons months later.

One can only wonder how many of the folks in some federal agencies genuinely, to the deepest extent of their hearts, believe such plans will help the American people.

The kicker is, a lot of people that did register did it for the free short barrel rifle tax stamp, which is normally a $200 "tax."
A brace could have been purchased for around $35 or even less as vendors offloaded them due to the rule change.