Let's talk sheep dip. No, not drinking the stuff.
Spooks have another couple of uses for the word. One means to fix the admin when you borrow people or equipment from the real world. Another, and the one we're interested in, is to arrange things so it's not obvious to other people how you got hold of information. Typically, if you have a secret source of information you want it to stay secret. But there's no point having the secret source if you don't act on it. All the fun of secrets is telling other people about them, after all.
So you've got a problem - how do I make use of the secret without letting slip the bigger secret of how I got it? The answer is sheepdipping.
Here's a second world war example. As basically everyone knows, the British had broken the Germans' primary radio cipher, taking advantage of work Poland and France had begun earlier and eventually creating an industrial system to pull in radio traffic, break it, translate it into English, analyse it, and distribute reports based on it. In the process, Bletchley Park as good as invented the computer. It was a priceless source of information. So much so that serious precautions were needed to avoid giving the game away.
The answer was to make sure that you found out the information you already had from the code break before you did anything about it. So, once the ships and soldiers were already on the move, a reconnaissance plane would go out or a patrol would be pushed forward to look in exactly the right place. As well as disguising the real intelligence source, this was also an opportunity to check that the source was right.
So why are we indulging in ENIGMA kitsch? Well. The Sun denied vehemently that it got access to the medical records of Gordon Brown's son. Actually it didn't, quite. It denied that they were the source of the story they printed, and hid behind the PCC about the tax files and the bank account and his lawyer's notes and God knows what else. But they found somebody who says he told them all about Brown's son out of the goodness of his heart. As God will be his judge. Yeah, he really said that. Everyone say "Awww."
He really said it; it's in the Sun. Anyway, he swore an affidavit.
Here's the sheep dip, though. Imagine if you're a sweaty 'bloid hack who's just been listening to the chancellor's voicemail. But, unlike the rest of them, you read books. What are you going to do? Take the risk of using the illegal secret surveillance as your source? What if some bastard with a Web site and a grudge goes through years and years of stories and pulls all the ones that are single sourced to conversations on the phone? You're smarter than that.
So, you look up somebody who might be able to give you the story you've already got. This shouldn't be that hard. You've already got more than enough information. That way, you're covered. And you get to check the possibility that the whole thing is a nightmarish trap. And there's a chance that they might provide some more juicy details if correctly handled.
The sheep goes into the dip, and comes out cleansed of its ticks and blowflies and worrisome legal problems, ready to be fattened up, shorn of its valuable fleece, and finally roasted and served with red-top jelly.
Alternatively, a slightly less underhand version. So this bloke walks into a bar. No.
So this bloke walks into a newspaper office. And he says to the barman...I've got this incredible story about Gordon Brown's sick kid because mine's as sick and I go to the same support group or clinic or whatnot. And you punch the conniving, insensitive Nosey Parker in the mouth and throw him out in the street. Right? I mean, who behaves like that?
No. This is a newspaper, dammit. You're not going to turn a chance like this away. But there's a problem. If his motives really are as nice as he makes out, what's he doing hanging around the News International building? Perhaps it's all bullshit. He's taking you for a ride. Newspapers attract enough crazies as it is; look at the comments threads. Throw around money for stories into the bargain and you're going to be beating them off with a side-handled baton, like the printers' union pickets. It's Brown's kid because he knows that will get your attention. Hey, you'd prefer Ulrika Jonsson's. But he's probably crazy and crazy people like politicians.
So you need to check on him. Quick. And because you've got a human source, you don't need to mention whatever you do to check up in the final story. Into the dip goes the sheep. Baa.
In my life I've had the pleasure of cleaning out not just a sheepdip but a cattle dip. It's a long job. My advice is to drain off as much liquid as possible - keep checking the filter on the firepump - and then pressure-blast it with boiling steam. Accept no substitutes, and watch your feet.