Honorable mention to Orson Scott Card for his not entirely scholarly understanding of evolution and his call for armed revolution if gay marriage were to be legalized (though in fairness some commentators failed to explain the context of the screed).
Rebecca Lee Carley is fortunately less famous and influential. She makes up for that in terms of levels of sheer crazy. Carley is a former MD and anti-vaccination activist whose licence to practise medicine in the state of New York was revoked in March 2004 as a result of general unhingedness (in fact, she was found ”guilty of practicing while impaired by a mental disability and having a psychiatric condition which impairs her ability to practice medicine;” more here and here) – though she is still cited as an authority among the more batshit antivaxxers. According to herself, Carley doesn’t need that license anyways, and the whole system of licenses and doctors and Big Pharmas is just a conspiracy against her ability to treat cancer.
Her claims about vaccines are the usual ones; vaccines cause autism, cancer, autoimmune diseases, and shaken baby syndrome (and Carley gives you ”personal stories of vaccine damage” to back up her claims). You can read her essay ”The True Weapons Of Mass Destruction Causing VIDS (Vaccine Induced Diseases) An Epidemic Of Genocide” on whale.to (no link). It is spectacularly insane, and includes (plenty of) deranged claims such as ”Bechamp proved that Louis Pasteur's ’germ theory’ of disease was incorrect due to this ability of organisms to transform and mutate based on the body's internal terrain (as Pasteur admitted on his deathbed).” Interestingly, on her website Carley also offers a phone number that you can call to get advice on how to reverse your disease with natural remedies, and she doesn’t even ”need to see you in person,” an admission that suggests that Carley may be semi-aware of the quality of her advice. Discussed here, with some interesting highlights from her problems with the Medical Board. One supporter, Arnold Gore, has his own take on that medical license thing on whale.to.
Diagnosis: The scary thing is that she still got plenty of people willing to listen to here, despite the incoherent insanity and combination of megalomania and paranoia being rather obvious.