A lot goes into an actor weighing the pros and cons of taking a role - chiefly among them money. But there's plenty at stake including reputation, adoration for the dialogue or character and being Nicolas Cage.
When Dennis Hopper was asked by his son why he took the part of King Koopa in Super Mario Bros., he explained he did it so he could have shoes. His son dryly replied, "I don't need shoes that badly."
However, on occasion, a script will come by an actor's desk that they have a more personal identification with; an autobiographical connection to the role that will allow the artist within to work through a personal, existential crisis or simply identify aspects of their own personality they'd be interested in exploring. Acting, like all art forms, is a therapeutic, often cathartic, way of tackling issues head-on - be them personal or political, and the very best exploit that to maximum effect.
Here are just some actors who took roles to make a statement, or at least exorcise some demons along the way.