From the WSJ article:

Some people list emergency contacts on an implanted tag. And others see potential for the use of the tags in medicine, though one big challenge needs to be addressed for those visions to become reality: Medical personnel or anyone else trying to help someone in a medical or emergency situation will need to have some way to know that the person they’re trying to help has potentially lifesaving information available under his or her skin.

From the Co-Exist article:

Imagine you’re moving apartments and shopping for new furniture at a couple of stores. You see a couch you like, but you’re not sure, so you leave thinking maybe you’ll return another day. But that couch doesn’t take well to rejection. It gets up, leaves the store, and starts following you around as you shop elsewhere and even after you go home having purchased a different couch. Then you start getting offers in the mail for new mattresses.