Mike Adams has an article on John Lott and Michael Moore where he writes:
The thesis of "Bowling for Columbine" is sometimes difficult to ascertain because Moore frequently contradicts himself in the movie. Nonetheless, I think that he is trying, above all else, to assert the following:
The United States has more crime than other countries (like Canada). The United States has more guns than other countries (like Canada). Therefore, guns cause crime and, of course, more gun control is necessary.
What Moore actually says is that Canada has as many guns as the US and does not make the assertion that Adams claims.
Moore could certainly be criticized on this point since comparable survey data from the ICVS indicate that only 30% of Canadian households have guns, as compared to 50% of US households. (See this paper by Martin Killias for details.)
Adams also writes about John Lott:
Some of my colleagues disagree with his recommendations for public policy but are completely unable to specify any flaws in his research or in his logic.
Adams seems to be unfamiliar with the papers by Ayres and Donohue, Rubin and Dezhbakhsh, Ludwig, Duggan, Black and Nagin, Duggan, Maltz and Targonski, Zimring and Hawkins, Hood and Neeley, Goertzel and Helland and Tabarrok. This is a little disappointing since Adams is actually a professor in Criminal Justice.
Update: World O'Crap weighs in, suggesting that Adams may have made up the stories about his colleagues.