If the subject of your film is interesting to a particular company, foundation or group, you may find partial funding there. I know one guy who made a film with a strong "traditional morals" message (good kid goes bad, winds up on the streets, helped to recover and return to home and hearth by an older runaway who found God) and he got substantial funding from a group of churches, despite the fact that the film is not likely to ever to be widely distributed or ever make a penny.
Another script that I heard about but have never read, involved a plot that actually portrayed a huge petrochemical pipeline as a positive influence on a Third World country. This guy was seeking funding support from (guess who) oil companies.
If you are making a gay romance, seek funding from gay advocate organizations. If you are making a film about cowboys, seek funding from a boot manufacturer, etc. Making a war movie? Military equipment wholesalers and firearms companies. Done correctly, product placement could finance the project and not intrude on the plot.
The idea is to secure enough funds to make the thing. Anything and anybody is a potential financial resource.
Sometimes I get to wondering what the deal is with all these mafia movies, you know? Hmmm.