Christian Science is neither.
Founded in the 19th century by a quack, Mary Baker Eddy, her book about faith healing spurred a movement that continues to kill people today. Although members keep dying, they still have 400,000 members.
They publish the well-regarded Christian Science Monitor. Although it's a good newspaper, it is dangerous in the sense of lending credibility to the religion. They also have reading rooms. There used to be one in the neighborhood where I grew up. I never went there, but they were near the public library, which made me think it was like a library but with religious stuff. How could people who encourage reading be bad?
They don't believe in any medical intervention of any kind. No eyeglasses, dental work, vaccinations, anti-biotics or pre-natal doctor visits. Like other faith-healing cults they let themselves and their children die from curable conditions. There's no actual science in Christian science. It's all mumbo jumbo -- even worse than faith healing, actually.
But what makes them particularly dangerous is that they are behind the ubiquitous "religious exemption" laws around the U.S. that have allowed the other faith healing nutters to kill children. These laws are well entrenched and hurting people all over the country and probably the rest of the world as well. Fortunately, deaths in other cults have brought attention to the issue of religious exemptions, and this attention may spell the end of it. Until then, they are on my list.
It may seem like a small thing compared to the evils of IFB, but in my book anything that harms & kills children rises to the top.