The social benefits are that our knowledge develops. You can argue that that is not a good thing because of the social upheaval it causes, but everyone who has argued that since we were cavement have been proved wrong.

For example, humanity's current best attempt at sustainable society is an unstable mix of democracy and capitalism, and in many countries that isn't working out too well - particularly for blue collar workers, but increasingly for your white collar workers too.

It isn't inconceivable that deep mind could design a better political system for the US, for instance, that resulted in broad consensus instead of virtual civil war. Or design a fairer tax system that meant more people could have fulfilling and enjoyable lives.

Whether deep mind's masters would apply it to those questions is moot, but the parent's point is that the huge resources being poured into Facebook makes it a much better example of the squandering of the efforts of our brightest and best.