It cites
17 USC 117:
(a)
Making of Additional Copy or Adaptation by Owner of Copy.— Notwithstanding the provisions of section
106,
it is not an infringement for the owner of a copy of a computer program
to make or authorize the making of another copy or adaptation of that
computer program provided:
(1)
that such a new copy or adaptation is created as
an essential step in the utilization of the computer program in
conjunction with a machine and that it is used in no other manner, or
(2)
that such new copy or adaptation is for archival
purposes only and that all archival copies are destroyed in the event
that continued possession of the computer program should cease to be
rightful. I assume he's referring to (1) above. But the adaptation is ONLY allowed if it's "essential".
So if my daughter buys a commercial program that's written for Windows XP, and wants to use it on her Vista machine, but it won't work correctly, and some hacker has created a patch that will fix the problem, she's allowed to use that patch to modify the program. Adapting the program to run under Linux would probably be covered as well.
If a blind person needs to have a program modified so that it will work correctly with text-to-speech readers, the copyright holder can't prohibit that adaptation, as it's "essential" to that person.
If we stray too far from those two kinds of adaptations (platform and disability), we lose our protection under 17 USC 117(a)(1).
There is nothing that allows adaptation to add new functionality that isn't "essential" (whatever that is). And even under that provision, there is still no right to redistribute the adapted work.
So I still say the guy's a wanker if he thinks we don't need a license to legally distribute his copyrighted work.