"During questioning, he told the authorities that he’d purchased the knives from military paraphernalia shops or...

"During questioning, he told the authorities that he’d purchased the knives from military paraphernalia shops or through mail order services. As for the shuriken, he hand-crafted them himself by repurposing lawn mower blades, so that he could throw them for his own amusement."

I think this needs to be a new leveling requirement for Chaos Monks.
http://en.rocketnews24.com/2016/10/20/man-arrested-in-japan-for-stockpiling-throwing-stars-and-knives-because-he-likes-ninja/