I guess the only way around it is to post a link and then paraphrase instead of quoting verbatim.
Wrong Planet is way too busy a site for one admin and some moderators to police constantly. The only way around would be to add a plug-in that would automatically check links and make sure the article isn't re-posted by more than 50%. Not that I like the idea of having to resort to that (I'd like to be able to quote an entire article, nitpick it in parentheses all throughout, and call the author a total fucking idiot if I feel like it.), but if that's what it takes to prevent a barrage of legal threats, then so be it.
I rarely go to Wrong Planet. It's just too busy to keep up with. I have been visiting and posting more lately, since I downloaded its widget, but not by much. The way I see it, it's like the Grand Central Station of Aspie forums. You have to take notice whether or not you like the way it's run. (Kind of like if there's a large city and you just happen to dislike the mayor. Doesn't mean the whole city's a bad place.)