Research carried out a few years ago focused on the average loss incurred during a bank robbery. It found that in one third of all robberies, the suspect got away with nothing. The research pointed out how, in comparison to the cost of the security measures to prevent and make bank heists harder, it would actually be cheaper to allow people to rob banks.
Of course, we wouldn't stand for such nonsense - and besides, banks have a duty of care toward their staff, a duty to protect them and prevent these crimes. And if the banks just allowed people to rob them, with no deterrent, it would happen all the time. It would actually encourage more people to do it.
Banks are, in the main, serious about their security, despite the costs far outweighing their current losses. Indeed, they aren't sitting back and just making do with the basic measures, such as protective glass screens. They've now started installing rising shutters too, which makes it even harder for the would-be criminal.
The addition of these rising shutters has made it almost impossible to physically rob a bank. The criminals now target weaker links in the chain; such as when the money is in transit, stored at a depot, or when it’s in an external cash machine. This leaves the inside of bank branches fairly crime free.
Today it was revealed that after carrying out the Christmas market truck massacre in Berlin, Germany - Anis Amri, the man responsible, travelled through Holland, Belgium and France to Italy.
This was despite being a known suspect, on a terror watch list, and armed with a gun.
The Schengen Agreement allows borderless free movement between many EU countries. Whilst this admittedly, is fantastically convenient for me and you as happy holidaymakers and law-abiding citizens, we have to remember how criminals such as Anis Amri can simply hop on a train in one country, and travel to another - with no passport or other ID required.
The terror threat in Europe has changed remarkably in recent times. For the first time in nearly twenty years we see both the numbers of deaths, and the numbers of terror attacks, increasing to levels not seen since the dark days of the IRA, ETA and the Red Army Faction.
Since 2000, the vast majority of terror attacks in Europe have revolved around Islamic extremism. These attacks were in the main, targeting the terrorists' own countries, or the countries that they were long term residents of. Examples of this include the Madrid attacks in 2004 and the London bombings of 2005, which accounted for most of the terror deaths in Europe over a ten year period - and were carried out by residents of those countries.
However, in the past two years, there has been a shift away from terrorists targeting their own countries. For example, those involved in the the Paris nightclub attacks lived in Belgium, and the Brussels Jewish museum gunman was born in France. It seems like tactics have changed.
Today, with Islamic-State-inspired attacks, we now regularly see suspects using one country as a base, while attacking a second country.
These people are doing things differently and attacking neighbouring Schengen countries rather than their own.
Moreover, as we see in the Amri case, the suspects often travel freely in a number of countries, following their attacks.
Moving across international borders is extremely difficult for police investigators, and it takes a lot of time to organise even the most basic transfer of data and evidence.
Not long ago, I was working on cracking an organised criminal network involved in the movement of money and weapons across Europe and Russia.
I was required to travel from the UK to another northern European country in order to collect evidence and interview witnesses and suspects. Even though the crime had taken place in the UK, it took 12 months just to get the paperwork before we could even travel there to begin our work.
Of course Schengen isn't to blame for these things. In itself it isn't the problem. It's just a weak security measure that is being exploited and abused.
In amongst this we also have the problem of identity. And again Amri lays bare how simple it is to come to the EU, make up a name and claim asylum. Once he exhausted or fell foul of the asylum process in one country, he simply moved to another, because Schengen allowed him to. He began using a different name, and started the whole process again.
And Amri is not the only terrorist who has abused the asylum process, nor indeed is he alone among terrorists who have taken advantage of the EU’s free movement to carry out attacks. We need only look at the attacks in Paris to see additional examples of this going on.
Many see any questioning of the Schengen system as politically sensitive or politically motivated, especially since the UK has recently voted to leave the EU. However, the UK isn't actually part of the Schengen area and never has been, so I do not feel I can be accused of any personal political motivations for pointing out the basic problems we are now facing or the current statistical trends.
Many are trying to suggest that it isn't Schengen that is the problem; that the free movement of millions should not be curtailed just to stop a few. But much like the banks, you can't just sit back and allow people to do what they want. The majority of people don't rob banks, but we have to put measures in place to prevent and discourage the tiny minority who do.
The cost to the EU of re-establishing borders, both in financial and political terms, will be considerable. And much like the banks, it is easy to see why they don't want to do so, when the losses are a tiny fraction of their profits overall.
Yet the EU has a duty of care toward its citizens, the same as the banks do toward their staff and customers. This isn't politics. It isn't anything other than basic common sense. There is overwhelming evidence that Schengen is failing to protect people. With both the numbers of attacks and numbers of deaths on the rise, you would think there would be more questioning of Schengen zone security by member states.
Alas, I see people trying to say that the reverse is true, that Schengen has actually reduced the number of deaths. But my experience of fighting organised crime and terrorism leads me to wholeheartedly disagree.
Will the EU do something about it? I doubt it. It sees the loss of a few lives, among the millions, as a tiny loss. But just like the banks, it can't look at it in this simplistic way.
If the EU were a bank, it would be the softest target around.
It would be robbed time and time again.
It would never implement even the most basic of security measures.
I do not believe the EU is serious about the security of its citizens.
David Videcette is a former Scotland Yard investigator with specialisms in organised crime and terrorism.
David's debut thriller, The Theseus Paradox, is set against the backdrop of the 7/7 London bombings investigation. Sales support the charity, the Police Dependants' Trust.
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