I can't find a reference for it, but I'm sure I've read somewhere that early on in the development of life assurance, they realised that the moral hazard created when offering policies which paid out on someone else's death was just too great, and it was made illegal, except for husband and wife. Even then there were plenty of suspicious deaths by arsenic. I've sometimes wondered if there was a similar case for making third party bets on the deaths of companies - e.g. credit default swaps - illegal.