It sounds like the allegations are for things that was be illegal in nature.
I think the expected way to handle something like this would be to write the calm factual email. If that goes nowhere then sue them. I don't think the public airing approach is the right one.
Suing is way more expensive and way more hostile than simply airing your grievances in public. And why not? That's what public forums are for. "Do nothing" and "sue them" are not your only options; we are part of a society, not merely party to a legal system.
It’s difficult to prosecute online harassment, and “hate sites and photoshopped images” aren’t illegal. There’s a right to freedom of speech in the US.
I think the expected way to handle something like this would be to write the calm factual email. If that goes nowhere then sue them. I don't think the public airing approach is the right one.