“The previously staid world of genealogy is in the midst of a controversial revolution. A handful of websites have turbocharged family trees with a collaborative, Wikipedia-like approach. You upload your family tree, and then you can merge your tree with another tree that has a cousin in common. After that, you merge and merge again. This creates vast webs with hundreds of thousands — or millions — of cousins by blood and marriage”.
http://www.nytimes.com/2014/02/01/opinion/sunday/are-you-my-cousin.html?_r=0//cdn.embedly.com/widgets/platform.js