Even though Michael Moore would like to pass himself off as a social commentator of some standing, he's nothing more than an entertainer. This is especially apparent after "Bowling for Columbine" and his childish and rather idiotic rant at the Academy Awards. He's good at making "mocumentaries", which hold about as much fact and reality as "Joe Millionaire" did...
As Moore is so concerned about removing ammo from the shelves of certain stores, suing the gun industry and generally creating havoc everywhere he can on this subject, I suggest he get some perspective and cover 9/11, where the largest mass-murder on American soil took place without a single bullet being fired...
...but then given his mind-set, he'd probably come to the conclusion to ban commercial flights, sue the airline industry and talk about the oppression that capitalism has thrust upon those innocent and put-upon Islamic militants.
In short, if it doesn't reflect the so-called "reality" that he belives in, he most certainly will distort things to make them appear to do as such...
I enjoy his works as much as I enjoy watching the Simpsons every now and them. Since I don't put much political or social belief behind what is shown on the Simpsons, the same applies with anything that Moore puts on celluloid.