It's usually stories that support the sharer's worldview, or that they (in some way), almost 'want' to be true. So a die hard vegan might be more likely to shar

It's usually stories that support the sharer's worldview, or that they (in some way), almost 'want' to be true. So a die hard vegan might be more likely to share a story about the dangers of eating meat than a barbecue enthusiast, and someone who believes their political side to be the 'moral' one is probably going to share stories about good things done by those on their side and bad things done by their enemies. So long as the story supports those beliefs the viewer holds dear, they'll believe it regardless of its inaccuracy. Same goes with media outlets if a fake story matches their political slant.