Recently I posted about a psychic who caused real harm to a woman with an autistic child. Now, thanks to the Bad Astronomy blog, I've found a site that collects evidence of the harm of psychics and lots of other superstitions. They also mention Colleen & Victoria Leduc's story, and also dozens of other stories about actual harm caused. This kind of resource is invaluable because many people deny that this harm even exists, never mind how widespread it is.
The only downside to a site like this is that a collection of anecdotes are not statistically significant because you don't know how many times these things happen. But the goal of whatistheharm.net is not to make people believe or not believe something, but rather to get them to think critically. And once you know that your naturopath's detox program might kill you, you have more information that you can use to evaluate the situation and you can take the next, important, step and learn more about what you're facing.