has anyone ever taken action for what they consider defamation (in this case slanderous accusations on a forum....not this one i hasten to add!) and if so, how did the progress?
Not done it Sam but think the rules on the internet are the same as any other public arena. Would advise you speak to a solicitor who may advise the demand of a public apology.
I haven't personally but have read up/studied loads of cases as a student.
The problem with a forum is it is limited to who would/could see the comments and you have to have some "Measurable" loss. Ie lose of work/jobs etc something tangible financially.
As far as I know, in order to proceed with a slander claim I think you need to prove that the post in the forum was read by very large number of people and that the outcome would/will be a loss of income for the person slandered.