From the nonpartisan, independent and nonprofit, the Center for Responsive Politics, the nation's premier research group tracking money in U.S. politics and its effect on elections and public policy.
One of the oldest debunking sites on the Internet, Snopes.com focuses on urban legends, news stories and memes. the also cite their sources at the end of each debunking.
Mercola is a doctor of osteopathy who has frequently been targeted by the FDA for promoting false, misleading and even dangerous medical advice. His site promotes products and his blog includes false and/or misleading information about medical topics.