Paper picks a story up.
Doesn't investigate too much. Just takes someone's word for it, especially if it suits their agenda, prints the story and then it gets picked up as it also fits in with someone's cognitive bias and they post it on social media
I've done the same. Read something, posted it, and it turned out not to be as first presented. But people rarely read any retraction, or any further evidence.. It just adds to their views of something and helps reinforce their own cognitive biases.
(And the obvious answer is No Shit, Sherlock)
Do people stop and think before reading something and posting it? Or do they just post it because it's something that's upset them?