Cantor’s broken window reminds me of my favorite Mythbusters episode - whether shooting into the air is dangerous, specifically whether a falling bullet can kill you.

They answered definitively - NO…unless you do it wrong, then YES.

A bullet falling from a few miles up will hit ~250 mph because of wind resistance balancing gravity. (It’s about 120 mph for a less aerodynamic falling person.) If it hit your skull, it can’t penetrate.

OTOH, if it goes up in the air at an angle, think a big lazy parabola, it’s kept some sideways motion to add to the down motion - then you may get killed. If your enemies have a vendetta and just shoot you, then blame falling bullets from the New Years celebrations or whatever, same thing - you’re dead.

Best. Mythbusters. Evar.