Why? The ATF (BATFE) was in the Treasury until the creation of the DHS because in 1934 the government felt a fiction of using its taxing powers was required to make full auto and handgun ownership too expensive except for the rich, requiring a $3,500 transfer tax in 2015 dollars. So it ended up with the same bunch as Elliot Ness's G-men.
But a sad thing happened to them not long after the Gun Control Act of 1968, sugar price supports made moonshine uneconomic, so they had all these agents used to busting stills and all that brutal drama with nothing to do, so they turned to this shiny, new law. Imagine a black legal gun dealer being coerced into selling guns to what he thought was the mob on pain of his family being killed, and Federal judges thinking this was just dandy....
Lots more where that came from, and for statistics, I'd suggest looking up the surveys on self-defense uses per year. Critically, the first data set was collected by gun controllers, and it demonstrated over a million uses per year. But it didn't ask participants how many times per year---most will probably be in high crime clusters---so later surveys by the pro-gun side, along with I'm sure an increased population, came up with figures as high as 2.5 million times per year.
Ah, here's the statistic I came up with: in the same period where both the population and number of guns owned by it increased by very roughly 50%, the number of fatal gun accidents per year decreased by 25% (800 to 600). I've heard this was largely due to mandatory hunter safety classes, but have no data on that except that the classes did indeed come into existence. If I was somewhat younger, I'd have had to take one when I retired to my home town back in Missouri.
ADDED: one other statistic you won't hear elsewhere: 5% of the age eligible, 19 and above population of Jasper Country, MO, has Missouri's very expensive concealed carry licence (note any state's will do). I gather we're not the only locality with such numbers, and per http://www.politifact.com/florida/statements/2015/apr/15/jeb... Pennsylvania has an amazing 9% + whatever's in the 18-20 age bracket. Florida has the most total, but with the smallest youth percentage and larger population it's slightly lower before factoring in the 18-21 population.
Ah, I knew there was a particularity good self-defense case in Chicago: http://www.chicagotribune.com/news/local/breaking/ct-uber-dr...
Uber driver stops a mass shooting (in a city in which a few years ago he couldn't own his gun, let alone legally carry it). That happens a lot, but it doesn't get reported because it would counter the narrative and obviously "citizen stops nutcase before he can shoot very many people" is much less newsworthy than a lot of people getting shot in one incident.
