First, guns don't protect, never have, never will. That is not the function of a gun. So anyone on their high horse should look to see if they're suffering altitude sickness.
Second, the design of these specific rifles is a non-issue. The gun market is inherently grey, which means regulation is minimal to non-existent. There's no white hats in weaponry of any kind. And, yes, that includes the re-enactment stuff I work with. I know that, recognize that and accept it*. No shades, just a thick, pea-soup foggy grey.
*That is why I despise "goody two shoes" arguments from both extreme camps. This isn't black, this isn't white, this is murky grey. I own it for my part, I hold nobody to a higher standard than I hold myself, but I refuse to hold them to a lower one either. Own it.
Third, the design of any regular weapon is a non-issue, but nothing stops you from designing an irregular weapon. With modern cheap hardware, a 3D printer and suitable low-cost materials, a person is quite capable of designing a 3-5 mile range sniper rifle that can be controlled via telerobotics from the home. We already know that low-cost cruise missiles with ranges in excess of 100 miles can also be built at home. With 3D printing, the costs become lower. With advances in technology (remember, the $5000 100-mile cruise missile was designed over a decade ago and it wasn't even close to what budget efforts could do), you can expect far greater ranges, far greater precision and far greater payloads today.
This, again, goes back to this being grey hat technology. If a black hat wanted to use such devices, we'd know about. Or, rather, the survivors would. America still exists, so black hats either don't have the courage of their convictions or they don't have the skill. Either way, they're not worthy of consideration. Worthy of being dumped into a deep oceanic trench, bu not worthy of consideration.
White hats? If white hats were building actively guided systems capable of that sort of range, you'd be seeing miniature computer boards running Linux, Squid and Tor relays launched into stable orbits that crossed nations with restricted network access. We don't. We see "peace corps" infiltrators attempting to install such devices directly, along with who knows what malware, causing international incidents and seriously destabilizing international relations, as part of neocon stupidity. White hats putting in a passive alternative with no hostile software and no damage to other nations -- that's an OBVIOUS way to do good for everyone and to minimize harm. But, no, they either don't have the skill or the courage of their convictions.
So it's all grey. That's all there is. Thick, pea-soup fog.