This is pretty near:

Detect breaches with Canary credit cards!

TL;DR;

Today we’re releasing a new Canarytoken type: actual credit cards!

1. Head over to canarytokens.org;
2. We give you a valid credit card (number, expiration, and CVC);
3. If anyone ever attempts to use that card you’ll be notified.

https://blog.thinkst.com/2023/01/swipe-right-on-our-new-credit-card-tokens.html

Swipe right on our new credit card tokens!

Thinkst Thoughts
@lojikil This is such a great idea! Simple concept yet powerful .