NY, Feb 18: Madonna's Maverick Films is prepping a feature based on the real-life events surrounding the 1971 Stanford Prison Experiment, sources said. The project follows the infamous experiment conducted by professor Philip Zimbardo at Stanford University to explore the psychology of evil by recruiting 12 college students to role-play prison guards and inmates. Zimbardo's experiment was discontinued when the participants began taking on their roles with harrowing results. Bureau Report