Is Westboro protected by the first amendment? Absolutely.
Is it destroying or otherwise hindering their abuse of that freedom by disagreeing with them and expressing that disagreement? Absolutely not, freedom is a two way street. The Government can not and should not interfere until there is a breach of peace but only to the extent of the the law allows.?
Did Anonymous do something illegal? Sure. Do I care? No.
Westboro is nothing but a group of hate mongers and do not have one ounce of common decency about them. They are not Christians in the truest sense of the term, they are agents of Satan period. Anyone that has an opinion about then are just as free to express that opinion. The government cannot by law tell them to stop their stupidity but the common citizen sure as hell can. It is as much their right to protest Westboro Satanic Church as it is for those morons to spout their garbage.