It is useful for breaking up speeches at rallies or protests. To do a popular theatre piece you should start by considering exactly the message you want to get across. Then think of images, characters, actions, dialogues, etc. You could write a short script that could contain words, actions, or a combination of both. Then practice your piece very well before taking it to the streets.
Popular theatre works well with television, because again that medium conveys images.
The News Media - The news media consists of radio, television, and newspapers. Mainstream media is often the method a lot of groups chose to communicate. However you should approach this area with caution. Again, think of what you want to say and who your audience is. Remember that the mainstream media exists to make money.