Went through CRL last with with the Ryans and security stopped me and insisted that I empty my brifecase.
When they couldn't find anything, they showed me the screen image and a lose AA battery (at a slight angle) looked like a small penkife. Once they were shown the battery, all was okay.
As I was repacking the bag, I commented that it was reassuring to see their diligence, they said "yes, well you might have been a some smart ass journalist trying to make us look like fools."
My first reaction was irritation, as these people should be looking after our safety, not engaging in CYA, but on reflection perhaps journalists do play a valuable role by keeping the security guys on their toes.