I think that Orac puts it pretty well in his recent post on Nicholas Gonzalez lamenting that he could have saved Steve Jobs.
As Orac notes, Gonzalez is a practitioner of "alternative" cancer treatments, based mainly on nutritional supplements and routine "coffee enemas," just in case you want to temper the joys of having cancer by blasting a cappuccino up your ass on a daily basis. Gonzalez bemoans how the biased media treats him and his fellow miracle workers, and how all those high-falutin', book-readin', "oncologists" get all the credit just because they treat patients with their fancy "medicine." Orac does an excellent job skewering the guy but I think the most important take-away is that Gonzalez's treatments have been shown to lead to worse results than the control group.
In other words, it's worse than doing absolutely nothing. He is harming patients by leading them away from conventional and effective treatments, and harming them again by actually promoting their disease rather than suppressing it. And again, can't stress this enough, coffee enemas.
That said, I think Orac may be mistaking ignorance for malice here. I try to take people at their word - which is admittedly a naive thing to do - and I think that Gonzalez believes his hype. I think he does think he can work miracles while the establishment tricks cancer patients into filing into monolithic hospitals to be ineffectually butchered. I do think Orac gives a pretty good framework for why he could believe that (namely for a lack of understanding of the scientific process). So I don't think Gonzalez means to hurt anyone, here. The problem is, he does, and that's my problem with quackery, woo and alternative medicine in general.
Now I understand the placebo effect. I understand that prayer can actually help people, even though I attribute that more to psychology than theology. I think there's a place for that in modern medicine. The thing is, it must be part of a larger, science-based treatment regimen. Even when the alternative treatment itself isn't harmful, if a patient forgoes conventional, effective treatment in favor of alternative techniques, they are being harmed. Time is critical for cancer patients. Waiting to see if some snake oil works can cut years off a patient's life, or cut it off entirely.
I'd love it if these treatments worked. I'd love it if I could be cured of this disease without being cut apart and exposed to dangerously toxic substances. I'd love it if I could drink a $0.50 cup of herbal tea a day instead of tallying medical bills.
But I can't. To hell with anyone who tries to make a buck off convincing me otherwise, no matter how sincere they may be.