I agree with Tim that in todays political climate, there is a greater likelyhood that the WTS could be held accountable for several things. I also agree that the shunning of members who were children when baptised might be something to look at from a legal standpoint. The best cases to put up front would be kids who baptised early, and then were DF'd or marked before their 18th birthday. Kids who came into the org w/o their parents being involved might be an especially sharp thorn in the orgs foot.
Also, I can't help but wonder about medical malpractice. I know that just telling folks that the bible prohibits blood transfusion, in and of itself, will not get the society nailed, but they have gotten very specific about medical procedures/substances, and strayed far from anything religious in doing so. Might be an area of exposure.