One of the common justifications I hear for the existence of user submitted, online family trees is that they may contain a hint or lead that you can use in your research. Someone out there in genealogy land may know more than you do and you can look at the online sites that let users submit their trees to find ancestors and connect with relatives. OK, the premise sounds so very reasonable, but is it really?
The answer to the question revolves around where and when your family lived and how many people in your family have submitted their pedigrees to online tree programs.
What do I mean by this answer? The two extremes might demonstrate the issue. I am at the far end of one extreme. I have thousands of relatives online with trees that include near relatives back only one or two generations. On the other hand at the other end of the spectrum, there are people whose ancestors came only recently from a country where there is little online activity. They may not be able to find even one other online tree that has an ancestor.
To illustrate my viewpoint, I entered one of my Great-grandfathers into the Public Member Trees search of Ancestry.com. I found 242 trees. I didn't make an actual count, but most of the trees were "unsourced." Many had only one or two sources. The tragedy and irony of this is that for just my Great-grandfather, Ancestry.com has at least a dozen valid historical sources. Even if there were some remote possibility that any one of these trees just might contain some kernel of additional information about my extended family, why would I waste my time looking? Why would I spend my time comparing 241 trees to my own on the offhand chance that someone just might have a clue to someone in my line?
Ancestry.com is not unique in this issue. I looked at the trees on MyHeritage.com. Their Smart Matches function finds 1,071 matching family trees. The first family site that comes up in the search has 17,364 people in its tree and there are 81 confirmed matches. I could spend all of my time simple going to family tree sites and copying out other people's information. Hmm. Maybe I could trace my family all the way back to Adam? What an easy way to do genealogy! Think of all that information sitting out there ready to copy and copy and copy. I could claim to have tens of thousands of people in my family tree. How important I will seem to be in the genealogical community. Of course, there would not be one shred of documentation or sources, but who need sources anyhow? When was the last time someone asked you how many people you have in your family file? (I get asked regularly). When was the last time anyone asked you how many sources you have in your family file? See, sources don't matter. Number do matter. Online family trees are great!
Now, in response, someone reading this (always optimistic) will think, I found my long-lost aunt or whomever when I found an unknown relative in a user submitted family tree. Then you fall into the category of those who do not have minions of family members copying each other and creating a virtual jungle of names and mostly inaccurate information online.
Let me illustrate with a simple example. My Great-grandfather was born in 1852 in San Bernardino, Los Angesles, California. Almost without exception, every one of the hundreds of online family trees, mine being the only exception, lock-step show his birthplace as San Bernardino, San Bernardino, California. But San Bernardino county was not formed until 1853 from parts of Los Angeles County. A technicality? Or is there something important going on here? Not one of these trees show any support or source for his birth. Why is this the case? If I find my long-lost relative in a hundred online family trees all listing exactly the same birth and death information, can I conclude that the information is correct? Apparently in the unreal world of online family trees that is enough to prove the point.
Now the ultimate question. Do I want to collaborate with all these people online? I will when I am contacted by any one of them asking me why I have Los Angeles county as the birthplace of Henry Martin Tanner. So far, not one person has asked me why and not one other person I have found has changed their online record to reflect the actual location at the time of his birth. The supreme irony of this whole situation is that both Ancestry.com and MyHeritage.com have the tools to provide valid online sources for almost every one of the people with their unsourced trees online.