Wikipedia Infoboxes (Wu and Weld, 2007) are a semi-structured source covering many domains with readily available authorship, and we produced our city population and basic biographic datasets from the most recent full-history dump of the English Wikipedia (taken January 2008).
attribution is difficult: if an author edits the page but not the claim within the infobox, is the author implicitly agreeing with (and asserting) the claim?