Actually, according to copyright law, the act of creating an original 'work' (art, software, book, picture, etc..) is automatically covered with the creators copyright.  Symbols or statement of this copyright is not required.  Copyright symbols and registration of the 'work' grants the creator with grounds to sue not only for initial damages but for damages due to future loss.  Without registration, you could only sue for initial damages caused by the infringement.  If you want to copy the work you MUST get permission to copy the work and create derivatives of said work.  Absence of permission does not give you the 'green light'.