Re: GNU licenses

[Alfred M. Szmidt]

   Nonsense.  He can be _held_ to the terms of the license if he does
   so.  You would not need to sue for compliance if acceptance
   happened automatically.

Section 5:

|      Therefore, by modifying or distributing the Program (or any
|      work based on the Program), you indicate your acceptance of
|      this License to do so, and all its terms and conditions for
|      copying, distributing or modifying the Program or works based
|      on it.

Acceptance doesn't happen automatically, it happens when you modify or
distribute the program.  If he doesn't accept the license, he is
breaking the law.  Simple.