What is differential privacy?
https://blog.cryptographyengineering.com/2016/06/15/what-is-differential-privacy/

Cool technique. Exciting thing is potential for formal definition, unlocking publishing lots of open data without handwringing. (Obviously many vendors have in mind more sharing with them. That's happening anyway, I see better privacy preserving tech existing as an excuse to force them to deploy it.) Enjoyed this bit as well:

On the flipside, as security professionals it’s our job to be skeptical — to at a minimum demand people release their security-critical code (as Google did with RAPPOR), or at least to be straightforward about what it is they’re deploying. If Apple is going to collect significant amounts of new data from the devices that we depend on so much, we should really make sure they’re doing it right — rather than cheering them for Using Such Cool Ideas. (I made this mistake already once, and I still feel dumb about it.)

Recently discussed in https://news.ycombinator.com/item?id=14618751