Way back when I was in primary school when winters were actually cold and men had beards a kid in my class was walking to school, on the schoolyard everyone was throwing snowballs at each other, as he was slowly strolling towards the entrance one girl threw one right in the face of this kid, *bam* eye infection and since then he has been blind.
Snowball fights are jolly good fun, just don't throw any at unsuspecting people who are not your mates and especially don't throw a whole box of snow in someone's car.