Normally, I criticize libertarianism, but there's a broad overlap between many crank movements and libertarianism. Anti-fluoridation movements are grotesquely crank, and have a widespread libertarian following because public health policy is a government (not market) activity.
About.com's Guide to Chemistry, Anne Marie Helmenstine, Ph.D., unfortunately includes her opinion of fluoridation in the chemistry topic.
Why I Oppose Fluoridation of Public Drinking Water lists a standard set of pseudoscientific arguments, and links to a bunch more About.com articles by herself and Mary Shomon, the About.com Guide to Thyroid Disease.
A really clear howler is this statement: "Fluoride that we put in water today will still be in water tomorrow. Fluoride doesn't magically disappear from water once it has been added." Evidently, Helmenstein has never heard of the water cycle and evaporation. No, she explains how fluoride is a permanent contamininant. In her article "How to Remove Fluoride from Drinking Water", she doesn't mention the possibility of drinking rainwater or your own well water, and she makes distilled water sound scary: "keep in mind that 'distilled water' does not imply that a product is suitable for drinking water and other undesirable impurities may be present."
Perhaps in a health topic such as Thyroid Disease, there's room for pseudoscience. But in chemistry, there's little excuse. And even more inexcusable, is that neither author identifies their opinion as a minority opinion or links to counterarguments.
Interestingly, the one About.com article they link to that supports fluoride is Relationship Between Florinated Water And Cancer, in the Holistic Healing topic. It would be more accurately titled "No Relationship Between Florinated Water And Cancer": maybe that's why they listed it, by accident.
But a search of About.com with the keyword "fluoridation" doesn't find any other articles supporting fluoridation, or opposing the cranks against fluoridation.