This is almost a Protest Warrior style tactic. In 2003, one of the PW founders named Alan, infiltrated ANSWER and carried with him a hidden camera.
In 2010, John Ruberry (the Marathon Pundit) visits Evanston, IL to infiltrate an Organizing for America (OFA) training session. OFA just so happens to be the political arm for President Obama. I think you'll like the post there's a little humor in it as Ruberry steals a line from a film Animal House.
That post earned a link to Instapundit, one of the most popular blogs on the web today. I just don't read it as much as I used to.