Back in the 1980s, when the internet was only available to a small number of pioneers, I was often confronted by people who feared that the strange technologies I was working on, like virtual reality, might unleash the demons of human nature. For instance, would people become addicted to virtual reality as if it were a drug? Would they become trapped in it, unable to escape back to the physical world where the rest of us live? Some of the questions were silly, and others were prescient.

The interesting thing about advertising is that the things that annoy us sometimes about it are really human. It's us looking at ourselves - and like all human endeavors it's imperfect.

I'm not in any sense anti-Facebook.

Here’s a current example of the challenge we face. At the height of its power, the photography company Kodak employed more than 140,000 people and was worth $28 billion. They even invented the first digital camera. But today Kodak is bankrupt, and the new face of digital photography has become Instagram. When Instagram was sold to Facebook for a billion dollars in 2012, it employed only thirteen people. Where did all those jobs disappear to? And what happened to the wealth that all those middle-class jobs created?

If you love a medium made of software, there's a danger that you will become entrapped in someone else's recent careless thoughts. Struggle against that.

I think that one can seek a way to eliminate war, and still agree that fighting the Nazis was a good thing.

We're losing track of the vastness of the potential for computer science. We really have to revive the beautiful intellectual joy of it, as opposed to the business potential.