How would warfare work? Would there be born a bunch of blokes all going to die in about 20 years time who join the army?
Likewise, if you were a criminal, well, you'd know the police sniper was about to get you?
Also, what about social issues...you'd got to a maternity ward and see the difference life expectancies of different ethnicities? Could it help your gaydar? "yeah, that guy's totally secretly gay, you can see he's going to come out and get beaten to death by rednecks"