When a criminal commits a crime, they try to do so without getting caught.

When that crime is a simple one like shoplifting at Marks and Spencer, whereby they run in, grab a handful of dresses and run out of the store; that’s a fairly easy risk for the would-be criminal to calculate, in terms of getting caught.

All they have to worry about is a few CCTV cameras and an overweight security guard – all risks that they can see in advance.

Yes, the police will come and report the crime. They will take some stills off the CCTV and hopefully, all being well, some eagle-eyed police officer will recognise the thief and they will get arrested.

The police catch criminals by their ‘footprint’- the things they leave behind by which they can be traced and found. Every single crime ever committed is solvable, every one, without question. It’s just a matter of having the time, money, resources and crucially…knowing where to look for the clues.

Now obviously criminals don’t want to get caught – so they employ methods to avoid this happening. In the case of the dress shoplifter, he or she might wear a baseball cap so the CCTV camera doesn’t get a clear look at their face, and they might have a car waiting outside with the number plates removed.

The police don’t put many resources into catching shoplifters so the counter measures to avoid getting caught can be crude and simple. As the crime becomes more violent, the loss is bigger – such as that involved in a murder or in a terrorist act – then the resources used to catch the criminal increases.

For the criminal, the counter measures to avoid getting caught then have to be more considered and complex.

So, clever criminals – when they’re considering planting a bomb or cutting off the head of a soldier – know that to avoid being caught they need to put a great deal of thought into how they’re not going to leave a big footprint behind. If you’re communicating with others you need to talk in code; you need to use unregistered pre-pay mobile phones; you need anonymous e-mail accounts; you need to talk in open spaces because your car or house might have listening devices in them; you need to turn your phone off and remove the battery when you are talking ‘dirty’ because the Security Services can turn your phone into a bugging device remotely without you even knowing; you need to use chat rooms in internet cafés.

And all that is before you’ve even committed the crime.

How do you think these people are located? I mean before they’ve actually planted a bomb, or cut someone’s head off? It’s simple – the criminals have made a mistake in their planning in the run up to the actual crime – and that mistake probably involved the internet or mobile communication of some type.

So when I read: “Thank you Edward Snowden – you’ve helped us win back the internet,” or when I see people complaining about the Security Services’ and Counter Terrorist Police’s “outrageous use of RIPA” (Regulation of Investigatory Powers Act 2000) to monitor us all for no reason – I wonder what these people think actually goes on in the background? Do they really think we care what porn sites they visit? How many phone calls they made to the premium rate sex chat line? What their mum had for dinner last night? That they are secretly gay?

None of that matters. We all have secrets. But when that secret is that you want to bomb an airliner, or a Tube train – lets hope that someone finds that before it happens, shall we?

You’ve not helped anyone that I care about Edward Snowden, you’ve just helped the criminals understand how things are done, and, now, you’ve put us all at greater risk.

Thanks for nothing, Edward Snowden.