Have you heard the phrase "don't feed the trolls?" Generally, if someone is saying hurtful things because they didn't know better, raising awareness is likely to help. If they're saying hurtful things to get attention, saying that they're hurting people and should stop is likely to be counterproductive.

I don't know enough to be positive in this case, but I'm guessing this is a case of "trolls", not a case of "ignorant people" (at least not ignorant in the sense of not knowing that they're causing someone distress).