"Autism Speaks" is the best known Autism charity in the US.

It routinely silences actual autistic voices, and shows basically no empathy for it. Any autistic person who can empathize with someone mislead by Autism Speaks is showing more empathy than it does.

Autism Speaks also tends to advocate a eugenics approach to "curing" autism, which many autistic people find unethical.

Hopefully useful as an example despite being a bit controversial / political on the ethical axis (I can't imagine any clear cut example that wouldn't be, aside from historical examples)