I could kill somebody with a brick- but a brick isn’t intended as a weapon.
Distinguishing between a phaser and the battery for one is really the only part of this that gives you pause?
I mean, any hardware store has a variety of tools that could kill and dismember a person- but that doesn’t mean that hardware stores are weapons stores.
Agreed though, that actually having that much power in a hand held device is dangerous.
Years ago, I read an book which pointed out a side effect of technological advancement: as technology improves, the number of people one person can kill increases. Before the club, it was pretty much 1:1. Then came the club, and it got easier for one person to kill multiple people. The bow improved that even further. Then came guns, and automatic machine guns- suddenly, one person could kill a *lot *of other people.
Add in bombs, and it gets easier. Nuclear weapons, you betcha: now one person with the proper tool can destroy an entire city.
We’re getting to the point- or may, in fact, already be there- when one person can grow a plague in his basement, and thereby wipe out a sizeable percentage of the world. Nanotech promises to make it even easier for one person to kill every single lifeform on the planet.
And there’s really not much we can do about it. It can’t be stopped. Maybe this is what happened to all of the aliens who are supposed to be out there- by the time they got to where they could start moving to new planets, they had already gotten to the point where one bug-eyed be-tentacled individual who had a bad day could destroy the entire damn civilization on a whim.
As much as I’d like to think that we could limit the really dangerous weapons… I don’t think it can be done. It’s getting too easy to make them.
I disagree. It is very easy to measure capability (former) and very hard to ascertain the “design” decisions (latter) behind why something was put on. I think you confused those two terms. 
(Unless I’m mis-understanding you and you do think that design decisions are easiest to quantify.)
As an example: A firearm can be equipped with a secondary grip. This acts to stabilize the firearm during discharge, but it can also be said that since you’re ready to fire again more quickly you can kill more people when you go postal.
The capacity is added stability. But, was it designed to be make the firearm more stable or to kill more quickly?
Anyway, in response to your specific question, there aren’t bullets that I know of that are designed to kill more than one person at a time outside of a shot that goes through one person and into another – but usually at least one of those people survive as it either went through a small part (arm?) of the first person or shed so much velocity that it doesn’t go far into the second person.
Outside of a clustering shot similar to buckshot (With larger pellets), I cannot think of a way to make each shot lethal to additional persons beyond the first target hit.
We have to expand the definition of “each time” from “shot” to “magazine”. In this case, the biggest contributor to death is emptying the magazine towards a crowd the fastest possible. We should ban fully automatic weapons. (The US already does, by the way.)
The next contributor to multiple death are the bullets with the power to go through an object and continue to the next object. Hollow point rounds expend their energy entirely into the object they hit first. They shatter on impact and the fragments dissipate energy more quickly (increased surface area is the easiest way to look at it) meaning that one object or person will be the entirety of the bullet’s impact. it would mean increased single-person lethality, but it would save lives by people being able to hide behind cover that isn’t otherwise adequate. We should mandate that all bullets sold are hollow points.
This could potentially save a lot of lives, at least in incidents where multiple people are targeted and not a single individual.
I look at it this way:
When has man not used technological innovation to his destructive advantage? Dynamite was designed to make construction and mining blasting easier. Of course, it was also used for warfare.
Gatling invented his namesake gun in the hopes of rendering warfare too horrific to continue doing it and simply force people to the bargaining table. That sure worked out, eh?
Every invention we have has been pressed into use as a weapon. Cars. Airplanes. Pretty much any object you can physically throw or stab with. Heck, I once witnessed someone get stabbed with a #2 wood pencil once. Not my ideal choice of weapons, but it certainly does speak to our race’s savagery.
The Navy is working on laser technology today that’s pretty effective. Admittedly, it’s intended to mount on a ship, not hold in your hand, but they’re planning to do things like burn up missiles in the sky, burn out small boats, and shoot down drones / planes, etc.
http://abcnews.go.com/Politics/video/us-navy-laser-test-takes-drone-18907970
I’m sure they’d be effective against people, and at some future point those technologies will probably be miniaturized, maybe even to the point of a handheld “phaser”-like device.
What are you considering “the past”? Semi auto guns with large capacity magazines have been available to American civilians for 100 years now.
For the purposes of this thread, “the past” is defined as “before now”.