On Thursday 03 April 2008, Bradley Hook wrote:
As you point out, the legality of copyright actions is based on permission of the author, and since the author has given implied permission, the act becomes legal.
*One* author/copyright holder has expressed permission. Countless others have not, and some have even taken technical-level steps toward trying to prevent it (eg, the patch to make Linux refuse to load incompatibly licensed modules).
Also, non-enforcement does not count as "implied permission" in regard to copyrights, only trademarks (and then the trademark is lost entirely).