I recommend Shunning and Radioactivity by Brad R. Torgersen. What he says about Vox Day, I second. Shunning has two effects: Either the shunned pretend to conform to end the shunning, or they don't. If you actually hope to convince anyone, you don't shun; you engage. And if you don't hope to convince someone who isn't violent, why shun them?
Rodney King asked the right question: "Can we all get along?" The shunners have their answer. The rest of us have ours.