I think Cambridge Analytica merely scratches the surface at the extent of psychological warfare, which is naturally largely controlled by big governments and big business whose interested are most closely aligned with big banks and unaccountable remote supranational entities.
However, here two establishment mouthpieces would have us believe that only the opponents of their beloved EU would dare use social media and other underhand tactics to sway the vote. My twitter feed is replete with promoted messages that are very much in favour of the EU, mass migration and Clintonite / Blairite politics.