I think where Alito's dissent is coming from is this: speech can be curbed by the State when necessary to protect those in the immediate vicinity from danger. The classic example we all learned in law school is that yelling "Fire!" in a moviehouse is not protected speech because it could cause a stampede where people could be hurt. Essentially, Westboro is using fighting words which can certainly, under the right circumstances, such as where they would cause violence to occur, be curbed. At least that is my take on Alito's dissent which I agree with. I am flumoxed to say the least as to why local municipalities do not choose to exercise their 10th Amendment police powers (the approopriate power in this case) to shut them down or at least remove them far enough away from the situation so as to render them much less caustic.