|Dear Webworker, if you really wanted to limit the use of this bulletin board for union supporters only, why was it set up so anyone could have access to it?
It is even concievable that a pro-union employee could place an anti-union message just try to stir up resentment against management.
Also, what proof do you have that Imerys' IT Department was involved in hacking your site last week? I believe there is a statement above this bulletin board that states that character defamation is prohibited on this workers' bb. I believe an unsubstantiated accusation falls in this catagory.
Come across with your proof or apologize to Imerys' IT Department.