pinheads.
"The signature itself, he points out, is a perfectly valid one backed by a self-signed certificate, and it's the check of whether or not that certificate has been issued by a bona fide authority that is absent. Yes, that music you hear is the sound of angels dancing on a pinhead, but nevertheless what the man says is true."
Angels on a pinhead? The usefulness of any signature-based scheme relies on being to verify who it was that made the signature. Anyone can sign anything: the act of deciding which "bona fide authorities" to trust is the exact analogue of deciding which countries' passports are acceptable: I'd expect the border agency to be quite good at that.


