Regarding the "we don't know how this stuff works" point, doesn't the FDA approve a ton of drugs where we don't know the exact mechanism of how it works? Do we need to know exactly and precisely how something works to know _that_ it works?
That is, the trifecta of bad decisions is black box functionality connected to an internet of hate (or unfiltered/tested input data) and given levers of power in society. Take away any one of those 3 and you're probably ok.
Stupidity is probably the biggest threat. Dietrich Bonhoeffer:
https://religiousgrounds.wordpress.com/2016/05/11/bonhoeffer...
Technology companies churn out things with barely a few weeks of testing at times and no oversight.