In a chain email I received recently, the claim was made that the urban-legend-debunking website Snopes.com has verified the information in the email. So, I read the article, and it clearly does not. The item was listed as a mix of fact and fiction. The explicit claim being made in the chain email was false, but the basis for the claim was true, even though it did not have the import assigned to it by the email. The person sending the email felt that merely referencing an authority with the claim it supports them was sufficient. It boils down to simply not taking the time to read.
In addition, this authority takes another form, where someone points out that many books/people/etc. have refuted or established an idea, as if that fact alone proves the case. This boils down to simply not examining the issue for yourself.
Most people are unwilling to invest the time to be fair when the way things appear to them already suits their existing outlook. This is just another way of allowing the ends to justify the means.