Sharon Tate Moody, In her TBO.com article titled "Mormon Web site handy, but be sure to examine details," reminds us that unsourced information is always a starting point for research, not an ending point (and, of course, even sourced information needs to be evaluated carefully).
Sharon uses the Familysearch.org site as an example in her article. Looking at the Ancestral File, Pedigree Resource File, and International Genealogical Index; she shows how the information can be conflicting, and how almost all of it is unsourced.
If you have been researching for any amount of time, you are aware of the dangers outlined in the article, but it is worth seeing another person's view of the problem. You can read Sharon's article at http://tinyurl.com/y3de7oy.