We now live in one world, one network, one technology, says Bruce Schneier, security technologist and chief technology officer of Co3 Systems, which means we can’t create technological systems that distinguishes legality or morality. In other words, we need to choose between security and surveillance: we can only build technologies that are secure for all users, or are vulnerable to all attackers.

Schneier spoke at BBC Future’s World-Changing Ideas Summit in New York on 21 October.

More videos from the World-Changing Ideas Summit 2014

Can tech create a new Renaissance? – Alexis Ohanian

Why we should live on other planets – Jeffrey Hoffman

Why everybody needs a drone – Missy Cummings

Is living longer really a good idea? – Ezekiel Emanuel

Discover more from the World-Changing Ideas Summit here. If you would like to comment on this, or anything else you have seen on Future, head over to our Facebook or Google+ page, or message us on Twitter.