Link to unauthorized copy of mfbook?

[Carl Sorensen]

In commit 4ff3911fee47369023e0588043d24f7bbd86cd86, a link to a pdf copy of
the METAFONTbook was added to the CG.

I believe that this link is a link to an unauthorized copy of the book.

At ctan.org, which is the official archive for all things TeX, the mfbook
package page ( http://www.ctan.org/pkg/mfbook ) includes the following
statement:

This file provides the source of the Metafont book, which is provided as an
example of the business of writing a book in TeX.

The source has Oprotection¹ against use to produce a document: such use is
only allowed with the permission of the Copyright holder and of the
publisher (Addison-Wesley).


Also, on Don Knuth's page, we find the following:

Copyright Infringement
The source file texbook.tex for The TeXbook has been available for many
years, and it begins with the following lines:
> % This manual is copyright (C) 1984 by the American Mathematical Society.
> % All rights are reserved!
> % The file is distributed only for people to see its examples of TeX input,
> % not for use in the preparation of books like The TeXbook.
> % Permission for any other use of this file must be obtained in writing
> % from the copyright holder and also from the publisher (Addison-Wesley).
> \loop\iftrue
> \errmessage{This manual is copyrighted and should not be TeXed}\repeat

>From time to time, however, people have flagrantly violated these
instructions, and posted PDF files of The TeXbook on the Internet.

Which of the words in those perfectly clear instructions do the people who
do such things fail to understand? Please, if you happen to see illicit
copies of these books, send a note address@hidden <mailto:address@hidden>
 so that our user community can apply peer pressure and/or legal action to
those who are unfairly exploiting our open-TeX approach.


A couple of years ago, there were lots of copies of mfbook.pdf available on
the internet.  Now it appears to be limited to a few, mostly hosted in .cn
domains.

I believe that these pdf copies are unauthorized copies, and we should not
link to them.

Thanks,

Carl