Having significantly more direct & current knowledge than certain posters here on the issue of the breach, I'd suggest it is not contractors (CO doesnt rely on them in the main), and that cock up over conspiracy is what is likely to have happened here. I suspect the person who did it made a very genuine mistake, the shame of which they will carry for the rest of their life. For a first offence, I wouldnt look to fire them, I would look to see where the training went wrong to prevent this from happening in the first place.
Let he/she who hasnt at one stage in their life in HMG/Military not made an error cast the first stone here.
As for the utter muppets who assume that the original issue of the thread is a subject worthy of discussion because apparently the bad guys know it anyway - I'm not sure I have enough words in my dictionary to discuss the utter contempt I hold you in for wanting to put national security at risk for the sake of your pathetic ego.