I have a suggestion for conference organizers that don’t want to see accusations of sexual harassment, even rape, lodged against high profile male speakers they invite.
Don’t invite any of them. Sure, you’ll see your attendance decline year after year, but you won’t be savaged online after the conference, you know 2 or 3 years later, with someone making claims that they heard from someone that knows someone that spoke to a woman who told them she was harassed/raped at your conference and you did nothing about it.
Oh, there were witnesses also. None of whom can be identified because, you know, by reporting a possible crime, that witness may be harassed/stalked/whatever. Just take the word of a person that doesn’t have any evidence.
And while you’re at it, how about having separate meeting rooms for men and women? That way, you’ve done your best to make sure you can’t be accused of not taking every precaution.