body: If someone infringes another's copyright and the owner publicly says it's ok, does he lose any further right to enforce it? 
  
  
  For example, party A has written a book creating a fictional character. Party B uses that character without notifying the copyright holder. Party A is made aware of this during a media interview and says that he is fine with party B's use and has no intention of suing. 
  
  
  How much does a public announcement like that affect the owner's copyright? Can he later change his mind and sue for infringement? If party B continues to use the character in future works, such as a sequel, can party A then sue? Can a third party legally use the character, acting on the assumption that party A has no wish to enforce his copyright? 
  
  
  
title: What are the ramifications of a copyright holder publicly stating they will not sue an infringer on that right?