Every now and then a tech comes along that is capable of busting through the perfectly legal obstacles presented by short sellers. It's going to be fun watching this unfold. Biel's pain relief tech works unbelievably well!
tZERO has 6 stock on it's exchange right now. They use blockchain to identify shares. There can never be naked shares. Trades are settled at the time of purchase, no two days to settlement. This is the wave of the future. Who ultimately becomes the standard is anyone's guess.