@Giroro and @Co Biy, the scandal is that psychological data was used by Republican campaigns to influence what people saw and knew about the parties campaigning without acknowledging they were doing so via facebook advertisements and posts. Cambridge Analytica took data people didn't know they had given, tried to figure out how you were likely to vote or what your election preferences were, and then targeted information at you to influence how you thought about the whole process. In the US, this is illegal. If you are working on a campaign, you MUST acknowledge this fact and state it outright. In this case, no one did, and it's clear that certain parties on the Trump side, I'm not saying Trump was involved, had access to a lot of very specific profiles that helped the Republican party cause.