I have noted, as I am sure many others have, the significant number of viral stories that turn out to be a hoax. These are perpetuated by people re-posting links they see that have an emotional component (often), while doing little to no verification to determine the veracity of the story or image in question.
There is a good article with some tips here: http://gizmodo.com/six-easy-ways-to-tell-if-that-viral-story-is-a-hoax-1732026737 where they offer links to tools that will simplify the process of verification.
Simply put, even a short snopes.com check often debunks stories, but it is bad form to blindly re-tweet, forward, re-post or otherwise propagate controversial (or really any) stories without verification.
I have seen a spike in these with videos and pictures related to the refugee crisis caused by the fighting across the middle east. While not aligning with the politicians and not getting into personal feelings on the refugee “importation” or acceptance, the argument is certainly clouded by the repeated posting of false images of “refugee” malfeasance that turn out to be from completely unrelated conflicts or issues. This noise in the social network is distorting the real dialog, and reducing credibility for those with valid examples or concerns.