Big Data as applied to terrorism (and more banal matters) is useful because it provides predictive behavior patterns without spending time and resources on locating the cause of the behavior. But should we abandon cause and just be concerned with potential effect? From Evgeny Morozov at Slate:

“The end of theory, which Chris Anderson predicted in Wired a few years ago, has reached the intelligence community: Just like Google doesn’t need to know why some sites get more links from other sites—securing a better place on its search results as a result—the spies do not need to know why some people behave like terrorists. Acting like a terrorist is good enough.

As the media academic Mark Andrejevic points out in Infoglut, his new book on the political implications of information overload, there is an immense—but mostly invisible—cost to the embrace of Big Data by the intelligence community (and by just about everyone else in both the public and private sectors). That cost is the devaluation of individual and institutional comprehension, epitomized by our reluctance to investigate the causes of actions and jump straight to dealing with their consequences. But, argues Andrejevic, while Google can afford to be ignorant, public institutions cannot. 

‘If the imperative of data mining is to continue to gather more data about everything,’ he writes, ‘its promise is to put this data to work, not necessarily to make sense of it. Indeed, the goal of both data mining and predictive analytics is to generate useful patterns that are far beyond the ability of the human mind to detect or even explain.’ In other words, we don’t need to inquire why things are the way they are as long as we can affect them to be the way we want them to be. This is rather unfortunate. The abandonment of comprehension as a useful public policy goal would make serious political reforms impossible.

Forget terrorism for a moment. Take more mundane crime. Why does crime happen? Well, you might say that it’s because youths don’t have jobs. Or you might say that’s because the doors of our buildings are not fortified enough. Given some limited funds to spend, you can either create yet another national employment program or you can equip houses with even better cameras, sensors, and locks. What should you do?

If you’re a technocratic manager, the answer is easy: Embrace the cheapest option.”