Hitler understood the demagogues' essential principle to teach or persuade is far more difficult than to stir emotion.

I do think the best thing for companies like Google and Facebook, if they are afraid of this ethical trap of advertising, is they should start letting people pay who want to pay and avoid some of the advertising.

I think you spend 50 percent of your mental energy trying to defeat ad systems.

If you really care about content, you should pay for it.

Facebook, when it began, like Google, was very resistant to advertising. They knew, like all - Mark Zuckerberg, like all good engineers, knew that advertising makes the product worse. But, you know, over time, they've been forced to increase the advertising load more and more and more. And the way they advertise is they - it's subtle but they know everything, you know, about everybody on the site.

Wikipedia, a nonprofit, is an enormously popular website but has managed to operate without advertising. And, you know, maybe it's a little simpler than Google and YouTube, but it does show there's another way.

There's always going to be a tradeoff between trolling and anonymity, and I guess that's the way life will be. And you can manage it, but you can't cure it.