More than you'd think, unfortunately. Tons of people share whatever random shit their friends share without any more thinking aside from the "if my friend shared it it must be true" thing. I've seen people insist up and down that something can't be happening because otherwise it would be plastered across their facebook feeds - as they also insist things are happening because it is. Like "voting fraud is a huge problem!" ... doesn't matter what the real numbers are, they see it shared and re-shared therefore it is a big issue.I see the same sort of confirmation bias show up with other reporting, though. Someone gets abducted, it's big news, for good reason. But in a country the size of the USA, there's bound to be a few happenings here and there - I see people see this reporting and instead of "Well, we had two in the country in about three months, and they were both in high-crime areas far away from me" it becomes "everyone is out to abduct everybody!" with paranoia to match.

As a species, we seem to be ridiculously bad at actual statistics. >.> (Better schooling on actually thinking about it would help, though)