Has anyone ever heard of this? We studied it in yr 12 Drama. It was invented by Augusto Boal, and it's basically a play performed to a group of people in a specific socio-economic group, about a situation of oppression that they are familiar with, and the audience get to say 'stop' whenever they want and jump in a take the place of a character and try to change the outcome. It's a really beneficial way of having people express themselves when they think they have no option. There is a range of other types of theatre similar to this, such as Image and Invisible, and even Legislative Theatre. If you ever get the chance to go to one, it would be a great experience and a new way of looking at theatre.
http://en.wikipedia.org/wiki/Forum_Theatre_(Augusto_Boal)
http://www.actnowtheatre.org.au/ANTSC.html