alt Hacker NewsNot so. Stallman created copyleft licenses as a defense against the current implementation of copyright. Copyleft uses the existing system of copyright to protect authors of free software from people who want to use copyright to restrict distribution. It wouldn't be necessary if copyright didn't exist.
Important nit-pick:
Copyleft was created to protect users of free software from authors/distributors who tried to use copyright to control the software running on the users' computers.