Trolley, you say posters are free 'to discuss anything we want to discuss and say anything we want'. Wrong. The law says different. In this particular case, the Contempt of Court Act applies. That's why all the newspapers are sticking to certain facts - name, details of charge, date of next appearence in court etc. etc.
If you are prosecuted and found guilty of Contempt of Court, you can go to prison. It applies to posts on the internet just as much as stuff published in the traditional media.