It wouldn't matter which journaling site fandom moved to, JF, GJ, IJ etc, the laws would affect them, too. If WB or other fans or whatever turned in someone for posting child porn, that journaling site would have to deal with it/suspend journals/be legally liable. It's the law that would have to be changed, not the journaling site. LJ isn't evil, it's just covering it's ass. Someone's pointed out these artworks, and they've reacted accordingly. It's not a witch hunt on their part, it's just cowardice on their part, they don't want the legal hassles and expense a law suit would bring. They don't want to be the new MySpace.

As an Australian, I can't even open sites like pornish pixies without breaking my country's laws and facing jail time if caught. I've had to leave the majority of HP communities (except Snape/Hagrid) because quite a few of them post unexpected child porn that is illegal here.