KingJulian
It might be worth checking out the legal position with regard to information published on the internet. If you publish a statement on a website or forum, even if that forum has a closed membership, there is absolutely nothing that you can do to stop someone else copying it and pasting it elsewhere. Hence, you need to be excessively careful about what you publish on forums, billboards etc. Newspapers and other media scour for snippets of information. Now obviously, they won't have your name, but they can attribute the comment to a group. There is no infringement of copyright, in the same way that if you give an interview to a paper, you do not have copyright over what you said.
If you publish a statement that libels another, then regardless of whether that statement was made on a closed forum or not, the libel exists and the person you libelled can sue you. The catch is obviously, that they have to be able to identify you. That's were the second line comes in. If you publish a defamatory statement on a website, there are sufficient ways to track you down. The ISP address you used will be logged, which will clearly identify the location of the computer used.
Re: cabin crew honouring deceased colleagues. Agree that this laudable, sadly though the way that BASSA did this was sleazy. Standing on the sidelines it appeared that the branch wanted people to wear yellow to support sacked and suspended colleagues. One of the ways that such solidarity could be expressed was by wearing a yellow flower. You could bring a yellow flower to commemorate the dead at Manchester as the flowers would all be going there afterwards. The implication given was that if you didn't attend the meeting, or attended but didn't have a yellow flower, that you were being disrespectful towards those who had died.
BASSA could have come across so much better if they had said that they were organising a flower laying ceremony on September 6th and invited all members to provide tributes. Completely separately from that they could also have had their meeting and invited all those attending to express solidarity for the sacked and suspended staff by wearing yellow. Don't you think that put that way it might have met with a better response from all the members ?