Related: I want to call out Firefox mobile for atrociously bad security UX around bad certs. The cert error message reads: "Fennec does not trust https : // hachyderm.io / because its certificate issuer is unknown, the certificate is self-signed, or the server is not sending the correct intermediate certificates."

This muddling of multiple error conditions, which becomes an outright LIE when the actual error is the main one that appears in the real world (expiration or wrong clock), makes it impossible to act on and fuels wrongful fears that a site has been compromised.