I think the point that paco was trying to make is this: Is it at all possible that someone could get hurt? If the answer is yes, then please don't shoot.
The <u>only</u> things I fire within city limits are paintballs, condiment packets, and tennis balls. The paintballs and condiment packets are fired in my backyard with a strong fence as a backstop. The tennis balls are fired straight up and barely drift, (this firing has been cleared with my neighbors, as long as it's at a reasonable hour.) I have also tested the impact of a tennis ball by firing one up then running madly as to be hit with it.
Spudgunning is a privledge, I hope this experience will cause you to be more careful with it.