Back in late 2006 I was stopped in Darwin airport and had my keyring confiscated. The keyring was a 3/8" spanner and about as long as my little finger.
The reason given was that it was a "tool", and that tools weren't allowed in the cabin.
When I pointed out that this set of keys had gone through just about every major airport in Australia that year the response was "We can't help it if no other airport in Australia does their job properly." (Darwin being the centre of international terrorism and all that
).
A written complaint later resulted in me receiving in the mail someone else's keyring (same size keyring but a shifting spanner). Go figure.
A few months later I was laughing about this with a mate of mine who was an officer in the AFP. He'd had an allen key taken off him by the same security team, despite him travelling in his AFP uniform!
DIVOSH!