Lee makes it very clear that "mandated" shunning is what is being argued against. The trouble with the slogan "Shunning is a Crime" is that it can sound like "avoidance is a crime", which can sound like "freedom of association is a crime". If you run with "Shunning is a Crime", then you'll get NAMBLA coming out and agreeing, saying "So stop shunning us!"
Mandated shunning is a very big problem. And for every complicated problem, there is a simple solution; and it is always wrong. There is no simple solution, but that doesn't mean we shouldn't be doing something about it. Starting with the shunning of minor children by their families is a sensible approach. Norway has had a crack at it. Even then, it's not perfect, but they did hit the WT where it hurts, in their wallet. If more governments did this, tying the shunning of minors to religious funding and charitable status, then it might cause the WT to back down on the shunning of minors.
But even then, we know that at the top, the WT is a pack of liars. They could well introduce a policy that looks like they are complying with the letter of "not shunning", while continuing to effectively do it in spirit. We are not dealing with normal, kind , rational people here. At the top, they are a bunch of cold-hearted killers, who happily condemn minors to death by encouraging them to refuse life-saving blood transfusions.
Another problem I see with this campaign is the lumping together of very different groups. The Amish are a harder nut to crack because they give minors the choice when they reach adulthood. They also don't tend to get government funding the way the WT does. So what works for the WT isn't going to work for the Amish.
So what is the answer? Certainly not one big, simple answer. What it will take is a lot of small answers, applied over time. The problem is big and complex, and will have to be chipped away at.