Google made a couple changes to mobile display ads to lower accidental ad click rates: blocking clicks on app icons, blocking clicks close to the edge of an image & adding a delay before ads can be clicked.
Belgium's privacy commission sued Facebook over privacy violations related to using like & share buttons on third party sites for ad targeting. Meanwhile Facebook shared information about an experimental AI algorithm they built which can identify most people in pictures even when they are not looking at the picture.
Raven published a comparison of Bing's vs Google's algos here.
While the Google mobile update was nowhere near as harsh to individual sites as Panda or Penguin was, Stone Temple highlighted a significant trend in downward rank movement for sites which were not mobile friendly over the month subsequent to the mobile update (though much of this is likely due to Google's increasing brand bias & a selection bias to where those sorts of large, trusted brands were more likely to have mobile friendly sites; while lesser known and smaller sites were less likely to use mobile-friendly designs).