Earlier quoted context omitted.
I've had one in my hand for 12 years. It has my contact card on it.
I'm not even sure which of many questions to ask first.. - Are you a furry? - Do you tend to wander off and forget who you are? - Who would think to scan a human for a chip? - Is this a common thing to do and I just don't know it? - Did you put the chip there or did someone else? - Or was it some kind of freak accident?
I think most people use them as a backup work badge or controlling other RFID readers (car key, smart lock, etc). Or as a party trick
It's not particularly common but I've met other people.
Some people selfinject but it's probably more common to go to like a tattoo parlor or body mod shop