Well, I don't know that much firsthand. I can tell you that my friends are pretty scared and that, if half of their fears are well founded, I'm scared too.
As for the plan, well it seems that these folks have been somewhat successful at getting documentation of events that the Semblers would really, really rather never come to light. Are the Semblers or their faithful followers capable of street-thug style violence? Well, the parents' group at SAFE certainly are.
So I guess all I can say is that I wouldn't write this off too lightly.