Roberts has also promoted anti-government conspiracy theories. In a June 2009 syndicated column, Roberts promoted a theory claiming that the United States government is building concentration camps all over the country to hold American citizens. In two columns published in VDare in August 2006, he promoted a 9/11 conspiracy theory that implied that the government had a role in the terrorist attacks. He alleged that the World Trade Center was likely destroyed by "controlled demolition" and not by the hijacked planes that were flown into the buildings. The inside cover of the 2007 edition of Debunking 9/11 Debunking by David Ray Griffin, a retired professor of theology who has been the leading promoter of 9/11 conspiracy theories in the U.S. for many years, featured a positive blurb from Roberts.