They are a group of hate filled satanists wanting to piss off WBC by doing homosexual rituals on a grave and declaring the deceased a lesbian. They hate WBC, it may not be as severely of an offensive act like protesting a funeral, but it's still hate. Their intent was to offend and piss off WBC just as the intent of WBC is to offend and piss off others. The actions weren't as severe, but the hatred behind it most likely just as bad. They are both wrong and both have their actions stemming from a hatred of another group. Neither is justified.
Review my original post. I said their behavior was immature and disgusting. Never did I say that they were the same, never did I say that when it comes to their actions that the satanists have done stuff to the same level as WBC. I posed the question that this behavior may make them "just as bad" by further clarifying that "just as bad" largely has to do with the hateful intent behind the actions. As it appears these people did what they did out of hate just as WBC does.