How did they bring this movie off?

...Much of this movie appears to have been filmed on the streets of the first Mayor Daley's Chicago. Until the late seventies, when the "Blues Brothers" was filmed there, Chicago was seen, because of prior censorship that was forced on film makers during the permitting process, as almost as difficult a place to make a movie as Moscow in the old USSR. The trivia section notes they did bother to get permits. That wouldn't be a problem for a small independent movie like "Getting Straight" in which a couple of actors were followed around the city with a cameraman with a hand held camera, but "The Spook Who Sat by the Door" was a action movie with scenes of crowds rioting, military and police vehicles, fire fights and explosions. I did read somewhere that parts of movie were filmed in neighboring Gary, Indiana, but that any of it could be filmed anywhere, given the politically and racially charged storyline.
People are just getting dumber, but more opinionated-Ernestine (Silks) in "The Human Stain"