All extremists who are likely to resort to violence, or threaten violence to intimidate people, are dangerous. Nothing to do with them being Muslims, Trans, right or left wing, or whatever. It is behaviour unacceptable in a civilised society.
The fact that JKR is first strongly criticised by the right wing press (the Mail) and then TRAs, and then individuals who identify as Muslims, is extraordinary and very worrying. The common link? The fact that she is a strong successful woman? The problem? Some men, however they identify, can't cope with this?
I hope she is OK. There is too much hate/violence aimed at public figures, admirable, likeable or not. David Amess, Jo Cox, but also Rebekah Vardy, all sorts of people.
"Hate" is seriously over used, but actual threats need to be clamped down on effectively and quickly whether by police, social media or whoever. It might be just an inadequate teenager sitting in his bedroom, but the fear created can be debilitating.
I hope JKR is OK. The Salman Rushdie attack must have been terrifying to any author who has previously faced threats.
(And if our visitors don't see this, or acknowledge this well...I don't know.)