My primary school banned pretty much anything that achieved popularity. Pokemon cards, Warhammer, GoGos, Yoyo's, Pogs, Beyblade, even fucking paper aeroplanes.
The paper planes story always makes me laugh though. I was one of the kids that satyed behind at the after school creche because my neglectful mother would pick me up an hour later than everyone else. Because there was nothing better to do, myself and the other kids set about trying to make the best paper aeroplane. So you can picture dozens of pieces of folded A4 gliding around a room.
A guy called Jack had seemingly created the best one that flew straightest and furthest. But that wasn't good enough. So I said "why don't you put a pencil in the end of it". He complied; what could go wrong? He tests it out, it flys fast but falls fast too. So he decides, the best way to get it to go really far would be to throw it up rather than straight forward. Sure enough, he throws it into the air and as it comes down, the deputy head mistress walks in and the pencil tipped plane went straight in her eye.
I never knew if she was actually blinded. But for the rest of our time at the school, this woman's left eye jiggled around indepent of the other one, though it's natural position was looking down, reminiscent of the googly eyes you put on sock puppets. Jack felt bad and got punished, but nothing happened to me. To this day, I still carry the guilt of knowing it was me who told Jack to do it. I tempted Jack with the promise of a faster paper plane. If only we had said "that's good enough" nobody would have got hurt. But no, we strove for perfection, with little thought to the consequences. I sometimes like to think of this as a metaphor for humanity; had we settled for less the world would be a safer, slower place with less tragedy.
Mostly, I just look back on the time I led Jack astray and a woman's eyeball got speared because of it.