I'm not quick to call for restriction of technology, but I see no use for bump fire stocks other than entertainment and to facilitate mass shooting. They reduce accuracy and are prone to cause barrels to overheat, which is why he needed so many rifles. They can produce the thrill of automatic fire and are handy for putting a lot of bullets into broad area in a short time, and that's about it.
I'm not anti-Christian. I'm anti-stupid.