Over the coming days you are going to see some pretty foul specimens saying that the Brussels attack is a reason to leave the EU. I want you to vote to leave but this isn't a reason. For nobody's sake will I lie and pretend otherwise. For the most part nothing the leave campaign says is credible. Leaving the EU doesn't end freedom of movement and it won't significantly reduce immigration for a very long time, and only after a second round of major negotiations. In any case it would have zero bearing on our vulnerability to terrorism.
Keeping a criminal conspiracy secret is not that difficult even with extensive surveillance. They start with open conversations and nobody bats an eyelid. It starts with a decision to do harm. It lives as an obsession thereafter. And there is nothing quite so careful and calculated as a human bewitched by a single track mind, bent on carrying out carrying out their goals. Often hiding in plain sight.
Once the decision is made, without intervention there is not turning back, no hesitation. A human who has decided the ends justify the means will permit themselves to do virtually anything while entirely convinced of their own righteousness and decency. It's unstoppable. In a hundred years time when every phone call and data transaction is recorded we will still be wondering how it still happens. And it will with the same regularity.
While people can be quite stupid I believe they can be driven by what some call the lizard brain; a high functioning intelligence for self-preservation. Like a computer programme. It does not stop unless interrupted. The ones who get caught are the ones who make mistakes.
Eventually big data will get good enough to contrast profiles with transactions and create watch lists of high probability, and one day our political ethics will wrestle with notions similar to pre-crime.
And that's where it has to be people making the decisions locally, with the people having ultimate authority. Even if we leave the EU we will still cooperate fully with Europol and may even keep the European Arrest Warrant. I don't have a problem with that from outside the EU where we can petition our own government to veto any such moves.
What worries me is no such veto or power will exist while the EU is the supreme government - and that is why we should leave the EU. A government we cannot say no to scares me more than any terrorist. Not least because a society where people are stripped of their power, driven to expressions of impotent rage, will only create more terrorism. This has always been a matter of democracy. Whatever the threat may be, the power must always rest with the people.