In the Prisoner of Azkaban, Hermione possesses a Time Turner, which allows her to be in two places at once. She and Harry use this device to frustrate the plans of the Ministry of Magic, while retaining a cast-iron alibi. And yet Hermione's possession of the Time Turner had previously been authorized by the Ministry of Magic - presumably by a separate department. Clearly the wizarding world has failed to embrace Joined-Up-Government.
All through the Half-Blood Prince, wizards mock the stupid authentication mechanisms invented by the Ministry of Magic.
"You have not asked me, for instance, what is my favourite flavor of jam, to check that I am indeed Professor Dumbledore and not an imposter, ... although of course, if I were a Death Eater, I would have been sure to research my own jam preferences before impersonating myself."
"I still don't understand why we have to go through that every time you come home. ... I mean, a Death Eater might have forced the answer out of you before impersonating you." "I know, dear, but it's Ministry procedure and I have to set an example."
In my view, Rowling has perfectly captured the kind of bureaucratic panic that causes Government Departments to disseminate such half-baked security schemes.
Into The Machine (updated now with a sensible title and a new URL) is an excellent blog documenting the serial follies of the British Home Office. And here is a great video of the British Home Secretary, singing the benefits of the UK Identity Card scheme. [updated to add] ... and I've just discovered this sequel thanks to Robin Wilton.