If the offending IP was a tor exit node, and dude was using tor at home during the same time period, that would almost certainly be appropriately admitted as circumstantial evidence.
He would of course be permitted to make an argument as to why that circumstantial evidence is weak and should not be given any weight.
Sure. I don't think a potential dictator would stand a chance if he/she didn't have the support of the US military, or at least the support of enough of it to suppress the rest. Either way, private-citizen gun owners are a rounding error in the equation. They just don't matter in this scenario.
Given that all guns, and a large number of non-gun objects (such as vehicles or big rocks) can be effectively utilized to kill nontrivial numbers of people in a soft target situation: is it possible that a more effective intervention may be found somewhere in the fact that several dozen young American men/boys feel compelled to murder as many strangers as possible before commiting suicide each year?
This also seems to me, at the very least, to be a less intractable/objectionable avenue. Less media coverage would probably do more to ease this problem than the banning of some subset of firearm.
