Hateful "Church" Plans to Protest Elizabeth Edwards' Funeral: At what point does free speech become harassment?

I am horrified to hear that the profoundly hateful, sick Westboro Baptist Church plans to "protest" Elizabeth Edwards' funeral:

Westboro Baptist Church to Protest Edwards Funeral

I pray that their presence will not in any way impact Elizabeth Edwards' youngest two children. I hasten to add that, of course, I also pray that it doesn't impact her adult daughter, Cate, or any of the mourners.  It's just that, upon learning of this horrible prospect, my first thoughts were of the two young children, Emma Claire and Jack.  I am especially concerned for them and I hope it doesn't affect even one tiny aspect of the experience for them. This should be a day that helps them process their grief and makes them feel surrounded by love, comfort and family. I don't want hate or ugliness to even touch them, they've been through enough.

Of course, none of us wants to see hate or violence touch any child, ever, but for the possibility of it to happen on the day of their mother's funeral seems especially egregious and awful.

I am one of the staunchest defenders of the constitution and civil rights that you will ever come across.  I am so grateful that we live in a free country, but to me, free speech ends at the point at which it becomes harassment.  If these people get too close to the church and hurl hateful attacks at the mourners, they would be engaging in harassment, not free speech, wouldn't they?  I mean, if they have to stay a certain distance back from the funeral venue and from the mourners, then I can see and must concede that tolerating them is the price we pay for free speech (even speech that most of us find abhorrent). But surely there is some law that would prevent them from verbally attacking mourners--including children--at a funeral?

I defend the right of everyone to engage in free speech, including speech that I find offensive and repugnant, because if they don't have the right to say what they want, I don't have the right to say what I want.  However, at what point does free speech morph into harassment?  When does a peaceful protest become a verbally violent attack?  I think the point at which people disrupt mourners, including young children who have just lost their mother, attempting to enter and/or leave a funeral, by spewing hateful verbal attacks at them could conceivably be such a point.  I think this "protest" just might fall outside the wide embrace of constitutional protection, as the rights of the mourners to gather peacefully, without being harassed, in order to grieve need to be protected, too.

If these hateful, sick people want to "protest" a certain distance away from the church, then I don't see how it can be stopped, frankly.  However, surely there is some minimum distance they can be legally kept back from the funeral venue and/or from the mourners, isn't there?  If not, there should be.  There is free speech and then there is disruptive harassment.  Where is the line?

I am going to pray very hard that their actions do not impact the Edwards family, particularly the two youngest children, in the slightest. If they do, I think it's a crime, literally...or it should be. It's harassment, it's stalking, it's something. Maybe John Edwards, an outstanding attorney, could make it a new cause of his to find some legal way to stop these folks from doing this at any future funerals, or if not stop them altogether, at least keep them from getting too close to the venue or the mourners.*  Freedom of speech is a precious right, but the rights of mourners to attend a funeral in peace must also be respected and protected.

* Edited to add:  I have learned that there is a current Supreme Court case (Snyder v. Phelps) pending regarding a past funeral protest by this "church" and whether it constituted free speech or harassment:

Washington Post article on Snyder v. Phelps

MSNBC.com article discusses Snyder v. Phelps