Mass surveillance is bad for you and it doesn't work

I have an op ed in New Scientist today, Mass surveillance not effective for finding terrorists.

Extract:

"Cameron seems to believe terrorist attacks can be prevented if only mass surveillance, by the UK's intelligence-gathering centre GCHQ and the US National Security Agency, reaches the degree of perfection portrayed in his favourite TV dramas, where computers magically pinpoint the bad guys. Computers don't work this way in real life and neither does mass surveillance...

Mass data collectors can dig deeply into anyone's digital persona but don't have the resources to do so with everyone. Surveillance of the entire population, the vast majority of whom are innocent, leads to the diversion of limited intelligence resources in pursuit of huge numbers of false leads...

Even if your magic terrorist-catching machine has a false positive rate of 1 in 1000 - and no security technology comes anywhere near this - every time you asked it for suspects in the UK it would flag 60,000 innocent people...

Law enforcement and security services need to be able to... engage in court-supervised technological surveillance of individuals whom they have reasonable cause to suspect. That is not, however, the same as building an infrastructure of mass surveillance.

Mass surveillance makes the job of the security services more difficult and the rest of us less secure."

Thanks to Jon White at New Scientist for the invitation to write for them.