So any regulation that fails to completely eliminate all potential for harm is instantly of no use or value? What about about decreasing the problem by keeping a subgroup of the crazy folks seeking to do harm from purchasing the means to do so?
How do you feel about felons carrying firearms?
I'm not going to be surprised when you have no problem with it.
Of course if a regulation reduces a criminal problem it would be considered to have value. But one has to weigh the good it does with the harm (and potential harm) a regulation might cause. As Wyoming has pointed out a handful of crazies has created havoc, for which the typical government response is to saddle 330,000,000 people with onerous restrictions. And at the same time it sets up the potential for huge government overreach. The regulations that have been bandied about on this board could ultimately result in the gov't having access to a mega database of the personal/private lives of many millions of people. A Samantha Powers type person might decide to use her security clearance to "investigate" her political opponents, and leak any embarrassing information to the press. Or a Donald Trump type person might choose to raid someone who is innocent of any misdeed but has said mean things about his tiny hands. As I have said repeatedly to those that seek government solution the onus is on them to show exactly what they want the government to do, exactly what procedures they they want, and show in great detail how it will solve the problem about which they are concerned without violating individual rights. I don't think that's expecting too much. Maybe we disagree.
As regard the topic of felons carrying firearms. I no more want to see them carry firearms than Medic waking around with a gun strapped to his thigh. If you mean do I think it should be illegal for a felon to have a firearm I suppose it depends on the felony involved. Has the felon served his time, paid the price for his sin? Would that matter? I don't know. Did I surprise you? (Probably not.)