I find the Adbusters article profoundly scary. I think you're right to be more concerned about that than about 'the Jews killed Jesus'. The latter is something that can be deconstructed, and for lots of people, has been. Plus, we have a largely secularized culture where overtly religious 'reasons' for hatred tend not to animate mass movements. But by its very nature a conspiracy theory can't be debunked. If you try, you're either a dupe, or one of the conspirators.