Only if the trajectory is almost vertical and the bullet is a small caliber. People get killed by celebratory gunfire all the time: http://en.wikipedia.org/wiki/Celebratory_gunfire

Bullets fired at any verticle angle will fall 'ballistically' which is a fore-shortened sort-of-parabolic curve due to air friction. If the angle is large, then the fall is essentially at terminal velocity. A shot at a drone is likely to be at a large angle.

The reports of 'celebratory gunfire' deaths are all necessarily speculative - the angle of the shot is impossible to measure. We can resort to physics to get a better answer than that derived from headlines.

Harmlessly? I know this is off topic, but....

A close friend of mine was killed by a stray bullet this year at a 4th of July celebration. She was in a crowd of thousands of people gathered to watch some local fireworks. The shooter was miles away and probably has no idea that they murdered someone.

http://statenews.com/index.php/article/2012/07/student_shot_...

I'm so sorry for your loss.

How horrifyingly random.