I'm curious, do these people ask themselves "where's the bullet going to end up ?" ?
Someone once told me if they asked me what time it was, I would tell them how to build a clock. Bear that in mind with my answer, along with the fact that I have spent some time with firearms and studying ballistics and they are among my favorite topics.
Do people in these circumstances ask themselves where a bullet will end up? Almost never, as evidenced by New Year's Eve casualties. Fortunately, physics coupled with the space human bodies actually take up in comparison with the area around them, make injuries rather rare and fatalities even rarer. Here is a statistic to explain this better: if everyone in London stood outside while someone fired a gun straight up in the air, there is a 0.064 percent chance of someone being struck.
Now for the physics aspect. A bullet starts to lose velocity the instant it leaves the barrel. The further it travels, the slower it gets. So a 9mm bullet that would certainly do me great harm at a few feet, loses it's potential danger the further it travels. Right now, we are talking about bullets fired horizontally or at an angle. Obviously, if fired horizontally, there is much greater chance of the bullet encountering an object, either living or inert but a 9mm fired horizontally will, by the force of gravity, strike the ground around 200 yards after leaving the barrel. The same bullet fired at an angle will most likely encounter nothing until it's trajectory takes it back to within say 20 feet of the ground. By this time, it has lost much of it's energy/velocity, but can still cause serious harm to an exposed person, depending upon the angle at which it was fired, the distance traveled, and the remaining velocity. Here is an example, using again, a 9mm handgun bullet: A 9mm bullet of 115 grains weight traveling at 1300 feet per second fired at a 45 degree angle can travel 2,455 yards (more than a mile) before striking the ground. At that time, it will still be traveling at 337 feet per second, enough to injure or possibly even kill someone. Rifle bullets, by virtue of their better ballistic coefficients and higher velocity have a much greater range and potential for damage, while shotguns firing shot rather than slugs, have poorer properties all around and therefore potential for damage. When injuries occur, they are most often from bullets fired relatively horizontally or at moderate angles. The steeper the angle, the less likely severe injury becomes due to loss of velocity, but possibility of injury still exists.
Bullets fired straight up into the air will travel a fixed distance, based upon the original energy and other factors. Eventually it will lose all upward momentum and be pulled back to earth by gravity alone. Thus, a bullet fired in such a manner will return to earth at around 147 feet per second terminal velocity. To put this into proper perspective, a slingshot can fire a projectile in the neighborhood of 260 feet per second. So such a returning bullet would certainly make it's presence known if it hit you, it is fairly unlikely to kill you.
So, why do we see so many reports of people being struck and even killed? It reflects back to the scenario I first spoke of, bullets being fired horizontally or at shallow angles. Bullets fired in this manner only lose enough velocity to become less than lethal over great distances.
Absolutely
NONE of this should be construed as endorsement of such acts which are reckless and should not transpire under any circumstances! Police, military and hunters are trained to always look for possible danger beyond their intended target, yet even they make mistakes occasionally. Enraged idiots firing at drones are very unlikely to think that far ahead and should be prosecuted to the furthest extent of the law.