I have had the unfortunate task of dealing with this group on an official level. First off, regardless of what you think of religion, Christians, etc., don't confuse what this group does as typically Christian or "church-like". They are not affiliated with any denomination, despite the Baptist name, and their "membership" is limited.
The "church" makes a living off of suing local government and counter-protest groups that "violate" their right to free speech. Several members of WBC (of which the majority are Phelps family members) are attorneys. Having to deal with them was quite interesting...they turn the vitriol on and off like a light switch. Out of the spotlight and "off the clock" they are quite cooperative, but when they have an audience they become the verbal and visual offenders we have seen on television. They will sue counter-protestors for violating their rights and sue the local government and police for not protecting their right to protest.
To give them any recognition just fuels their further activities...if Arizona's enactment of the law keeping the protestors further away from funerals holds up to legal challenge, it will go a long way towards negating the shock value of these type of demonstrations.