Neither. There just isn't that big a fraction of the earth's surface that's inhabited. You should regard this similarly to someone firing a gun into the air.
If you fired a gun into the air in the UK I'm pretty sure that a) You'd get in pretty serious trouble for it by itself and b) if you killed or injured someone that trouble would be significantly multiplied to the extent you'd end up in prison. I think it would be a manslaughter charge.
In most areas of the US recklessly discharging a firearm into the air would also get you in serious trouble (even in rural areas) along with a (lesser) murder charge if you killed someone.
FWIW, according to a study published by the National Library of Medicine, "celebratory gunfire" accounts for 4.6% of all stray bullet-related deaths and injuries:
Right. Just as with the space debris, it should be illegal and prosecuted but it's quite unlikely to actually kill someone when only performed a few times. It's the habit you have to prevent.
