Not that I'd want some centralized chips, but there are some really interesting use-cases for self-sovereign self-installed implanted microchips.

To be fair, harder to dispose of than a tag in your clothing, but to each their own.

It's just a simple nfc tag, but manufactured in a bio-compatible form like a pet tag.

You can write whatever data you want to them, be it access control credentials, vCards, urls, text...

In this case I was using LNurlW to create a LN faucet so people could receive sats just by tapping their phone to my hand.