It is theoretically possible to suppress the vote using Psychological manipulation tools on the targeted masses

And this was done through Facebook. It's not that Facebook was aware what was going on it's just that when you have over 2 billion people on Facebook worldwide keeping track of everything being said and done would likely be impossible for any company that actually wanted to stay in business.

So, to say any social media company is vulnerable to mass psychological manipulation of the masses is the understatement of the year.  I have seen what psychological tools pointed at a certain demographic of people are capable of while studying at UCSC and at other colleges along the way.

So, it is not surprising to me that some people were prevented from voting by disgusting them with Fake news and how other demographics were encouraged to vote for Trump by manipulating them also with Fake news.

Both manipulating people to vote and manipulating people against voting is most easily done with fake news the last 2 weeks before an election. Because the people don't have time to research what is true and what isn't often in those 2 weeks time before an election and after the election it is too late to stop the fake news that just ruined the validity of any election past, present or future.