Trivia: The first draft of the script involved Dana being kidnapped and taken to Scotland, where she'd discover an underground world of fairy-tale creatures, fairies, monsters and witches. The Ghostbusters would then have to travel to Scotland to save her. Dan Aykroyd has said that the script was simply "really too far out... too inaccessible."
Trivia: A great deal of the film was changed after poor test-screenings. In the original cut, there's a scene where Ray is possessed by Vigo earlier in the film and dangerously drives the Ecto-1 through the streets. Eugene Levy also appeared as Louis' cousin who helps the Ghostbusters get out of the hospital. There was a sub-plot of Louis trying to catch Slimer but being comically out-witted every time. Several scenes were substantially longer. And the entire climax was completely different.
Trivia: On the theater marquee, the film "Cannibal Girls" (with Eugene Levy and Andrea Martin) is seen. "Cannibal Girls" was directed by "Ghostbusters" and "Ghostbusters 2" director, Ivan Reitman.
Chosen answer: After the initial high of saving the city from Gozer wore off, they were blamed for the danger in the first place and sued out of business. The restraining order was additional insult to injury.
Captain Defenestrator