GeneaWiki is a tool created by Magnus Manske to visualize the family of a person using data pulled from Wikidata.
I used the GeneaWiki tool as an example use of Wikidata in a presentation a year ago (2014) and below you can see the screenshot I took from it. It shows 10 people in Barack Obamas family tree / web.
When creating a new presentation this year (2015) I went back to GeneaWiki to take another screenshot and this is what I found!
Around 30 people now! :)
Yay, more data!