Yes, there are definitely sites out there that encourage all kinds of dangerous behavior (I am SO resisting the urge to link to the FDA site right now.... *self control*), including tips and tricks for furthering your eating disorder, hiding it from family/doctors, "success" stories, etc. - you can look them up fairly easily if you'd like.
I don't think I'm freaking out about that thread, just... I stopped reading it... I really don't think it was "going there" either, but I've worked with enough eating disordered teenage girls that it felt uncomfortable for me - MY hangup, I think.
Like PaleoBird said, lots of non weight-loss reasons to fast.
The reasons I fast include weight loss at the moment, but I'm sure I'll continue to fast when I find my body composition more ideal - I find several aspects beneficial for more than just weight loss.
I used to do 1-3 24-hour fasts during the work week (dinner, then fast until I could do my half mile all-out swim the next day at 7pmish, eat afterwards), and it was probably the healthiest I've felt as an adult. That healthy feeling alone is reason to keep doing it!
Right now, for me, it's all about feeding myself when I'm hungry and not feeding myself when I'm not - going solely by my hunger, I'm delaying or skipping lunch (and breakfast too, if I'm not hungry), and I throw in the occasional fast that's not dictated by lack of hunger, just to change things up a little.