Cnry
Cnry makes it easy to publish and keep track of warrant canaries
...The idea of using negative pronouncements to thwart the nondisclosure requirements of court orders and served secret warrants was first proposed by Steven Schear on the cypherpunks mailing list. Even if you don't need a warrant canary, you can publish a Cnry as a pet that you need to feed once in a while (via the keepalive function) or it will expire. How often you need to feed it is configurable in the contract. Warrant canaries are only useful if someone's paying attention. So anyone can call the watch function which will mint a WATCHER nft that keeps track of that activity. ...