I don't currently see any benefit in having stocks in a bitcoin like system. It's probably better to just have companies subcontract out their shareholder registry management to a company specialized in doing that sort of thing (exactly how they do now infact). Ultimately the investors are required to trust the company they invest in - if they don't there are a million ways things will go wrong and having the shareholder registry in a block chain won't stop that. With bitcoin as a currency there is now no single point of failure, with company stocks there is always a singe point of failure - the company. Having the company manage it's shareholder registry (or more likely subcontract it out to a register management firm) doesn't make any difference. If people want to invest in totally black companies that aren't registered with any government the same thing applies - the black company can still manage the shareholder registry with no additional risk. You're just trusting the management.. but you have no other option.