By default in the non-forum world, authors own the copyright on their own creations. This is an automatic right of the creator of the work, so technically the creator of the post is the copyright owner. However, by posting on a forum, you would have accepted the terms and conditions when you join a forum that covers this type of publication and what it implies. In posting you are accepting that your creative content (ie your post) will be published by the forum administrator and owner, and also that they have the right to edit or do what ever they like with your post as they see fit.
But does that mean that when material is publicly posted in a forum that this implies transfer of copyright ownership? The copyright lawyers can not even agree on this. The reality of the matter seems to be that there is no clear legal precedent yet made on this matter, and therefore until there is, then the issue will remain vague and uncertain. It has never been tested in court, let alone the issue of legal jurisdiction as to country of the Administrator, the country of the servers the forum is hosted in, etc.
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