[tshaddox]

I'm aware of the assassination market concept, but there's nothing particularly unique about prediction markets. Nearly any conceivable market can be influenced by someone willing to commit violent crime. That obviously includes many normal securities markets.

Legal systems certainly should restrict markets where the incentivize is sufficiently direct (e.g. actual date of death prediction markets). There's a blurry line between what constitutes a sufficiently direct incentive, sure, but there are lots of blurry lines when it comes to legal systems.