Even guerilla films require at least a little bit of cash to keep them going. Although actors and crew are often not paid (usually there's some sort of deal worked out where they get a percentage if the film is sold for distribution), there are ancillary costs that have to be covered, like equipment, film processing, even meals. Some producers put up their own money or try to raise it via friends, family and online campaigns like Kickstarter and Indiegogo [source: Fera].
Some guerilla films do have private investors. Often, however, those films still choose to avoid permit costs in favor of spending the money on other aspects of the filmmaking process.
Filmmaker Robert Rodriguez, who made "El Mariachi" on a $12,000 budget had to come up with the last three grand himself -- as a human guinea pig for a cholesterol-lowering medication, which required that he be checked into a medical facility[source: Broderick]. Dedication has a name, my friends, and that name is Robert Rodriguez. His movie was filmed in Mexico on locations he could get for free and most of the scenes were shot with just one take.
Fans of 1984's "The Terminator" might be shocked to learn the cult favorite was a long-shot with such a small budget that it was made guerilla-style; this is actually how director James Cameron was trained by Roger Corman. During the shooting of the final scene on a deserted road, a policeman drove up and asked for Cameron's permit. He pretended he was doing a student film and was let off with just a warning [source: Moore]. I'm guessing he doesn't have to sidestep the rules (or the permit costs) anymore, thanks to his stellar achievements since.
Academy Award-winning film "The French Connection" managed to film guerilla-style all over New York City, despite having a pretty big crew [source: Kroll]. Another head-scratching example is "Escape From Tomorrow," which was filmed over a period of weeks at Disneyland and Disney World without permission of any kind [source: Burchette]. According to Kroll, the crew managed to dodge Mickey's wrath by using handheld (read: touristy) cameras and surreptitious communication methods, like cell phones instead of walkie-talkies.