"A study by the U.S. Centers for Disease Control and Prevention (CDC) found that 80% of celebratory gunfire-related injuries are to the head, feet, and shoulders.[6] In the U.S. Commonwealth of Puerto Rico, about two people die and about 25 more are injured each year from celebratory gunfire on New Year's Eve, the CDC says.[3] Between the years 1985 and 1992, doctors at the King/Drew Medical Center in Los Angeles, California, treated some 118 people for random falling-bullet injuries. Thirty-eight of them died.[7] Kuwaitis celebrating in 1991 at the end of the Gulf War by firing weapons into the air caused 20 deaths from falling bullets.[7]"
http://en.wikipedia.org/wiki/Celebratory_gunfirenot according to the CDC, and LAPD ...
Myth.
they fired perfectly straight up on myth-busters, which is somewhat different ballistically, and not pertinent to our discussion about how much energy a bullet carries at distances longer than it's optimal range. as i recall they also stated that such injuries were documented fact and that firing at an angle off of pure vertical would allow the bullet to carry much more of its energy through the entire flight ...
http://kwc.org/mythbusters/2006/04/episode_50_bullets_fired_up_vo_1.htmlwhen Mythbusters tried this the bullets tumbled down at terminal velocity, more likely to give you a headache than kill you.
Rats, I wasn't going to get involved in this thread. 