In theory this can be circumvented by regularly publishing “as of MM YYYY i have not received a warrant from government”.
In practice—we would not know if someone was forced by government to produce a particular canary. Government that can force someone to lie would likely be also able to force someone not to disclose they were forced.
Another thing government can do (and in case of Australia did) is to prohibit canaries in some cases alltogether by making it illegal to “disclose information about the existence or non-existence”.
In theory this can be circumvented by regularly publishing “as of MM YYYY i have not received a warrant from government”.
In practice—we would not know if someone was forced by government to produce a particular canary. Government that can force someone to lie would likely be also able to force someone not to disclose they were forced.
Another thing government can do (and in case of Australia did) is to prohibit canaries in some cases alltogether by making it illegal to “disclose information about the existence or non-existence”.