The problems that this creates are demonstrated by what happens when technically skilled users are required to work with certificates.
If you haven't already seen it, I highly recommend Don Davis's "compliance defects" paper (and slides!) available at http://world.std.com/~dtd. Abstract follows:
Public-key cryptography has low infrastructural overhead because
public-key users bear a substantial but hidden administrative burden.
A public-key security system trusts its users
to validate each others' public keys rigorously and to manage
their own private keys securely. Both tasks are hard to do well,
but public-key security systems lack a centralized infrastructure
for enforcing users' discipline. A "compliance defect" in a
cryptosystem is such a rule of operation that is both difficult
to follow and unenforceable. This paper presents five compliance
defects that are inherent in public-key cryptography; these
defects make public-key cryptography more suitable for server-to-server
security than for desktop applications.
-- Rich Salz, Chief Security Architect DataPower Technology http://www.datapower.com XS40 XML Security Gateway http://www.datapower.com/products/xs40.html
