I opened the tab --> paywall.

I opened the tab in incognito --> paywall.

I clicked through from Google News (https://www.google.com/search?q=google+news+facebook+reserac...) --> suddenly no paywall with a top banner "You are reading a preview of a paid article" (but it's the whole thing).

I clicked through from Google News a second time in a new tab --> paywall again.

¯\_(ツ)_/¯

Here are some free sources:

Ex-Darpa Head Regina Dugan Leaves Google for Facebook http://www.wired.com/2016/04/regina-dugan-leaves-google-for-...

Regina Dugan exits Google to lead Facebook’s Building 8, a new R&D lab http://techcrunch.com/2016/04/13/regina-dugan-exits-google-t...

Facebook hires Google 'moonshot' exec for R&D http://www.usatoday.com/story/tech/news/2016/04/13/facebook-...