Cats have them. And plenty of other pets have NFC (near-field communications) chips implanted so that they can be identified. So why don't humans? Imagine the convenience. No need to carry keys or credit cards; your car can recognize you by the special identification number carried in the chip. Terminals for chipped credit cards like they have in Canada and Europe let you tap directly from bank account to store. No more entering passwords for your computer or phone. It's an electronic business card. If you get mugged and your wallet and phone are stolen, you can still be identified, just like your puppy. Then there's our aging population. After all, a chipped wandering grandma would be a lot easier to find and identify.
 
In Stockholm, they are trying out chips at a co-working space, installing card readers at the door and on the copier so you can walk around like you own the place.