A strategy against Fred Phelps

I heard on NPR yesterday that Fred Phelps was planning to "protest" at Coretta Scott King's funeral.  Here is an excerpt from NPRs website:
As Atlanta readies for Coretta Scott King's funeral Tuesday, police brace for Fred Phelps and members of his Kansas church. Phelps has exploited funerals for virulent, anti-gay protests. The controversial preacher says state efforts to neutralize his protests violate his First Amendment rights. Frank Morris of member station KCUR reports.

While I agree that the right to free speech is a vital part of our constitution, and I detest defending such hate filled protests, I do believe that state efforts will to silence him will fail.
As an alternative, here is a proposal.  I think anyone who has been on the receiving end of his protests, especially soldiers families, should sue the SOB.  
Sue him for slander, sue his church for damages, sue anyone associated with any of his protests.  File a new lawsuit for each new protest.  Tie up all his resources not with defending his right to free speech, but with trying to defend his hate-filled slander.  
Make sure he has to be in court every single day for the rest of his life defending his hateful, disrespectful practices.