Im thinking like an micro chip implanted in our body. This system is not out of the picture because how we discover things every year, it is not impossible that in the future this things may happen and it will boom like btc.
Thats posible even if many years ago that microchip is useful to determine the place where they belong. I think because of a high level of thechnology microchip device may applied for adfitional feature for payment from bitcoinwho knows soon it will happen because year we will have new additional creation and invention for our good nation.