https://www.youtube.com/watch?v=bIWIstLQXUk This is a txt file commonly found on dark net sites, where you can access it through pretendthereissomedarkneturlhere.onion/canary.txt.
origin
This canary term was derrived from the fact that real life coal miners would often bring a canary with them in the mines, since canaries react strongly to toxic gases, and if the coal miner would see the canary in distress, they would know its their time to leave.
Use case
The purpose of canary.txt was to signal to other users that this website is operating under their own control. It has not been siezed and used as a honeypot by federal agents.
If the canary text file has not been updated, or it is removed entirely, then that is the distress signal seized by feds or competition. do not go