While checking the licensing of this Python library, we stumbled over this note in https://github.com/chardet/chardet/blob/master/tests/README.txt:

These test feeds were downloaded from random sites while I was developing the Universal Encoding Detector.
Each feed is copyright its respective publisher.

In our project team, there are major concerns that redistribution of those files might not be allowed. Looking into history of test/, some other tests were also taken from https://github.com/errepi/ude/tree/master/src/Tests/Data which states that tests are copied from Wikipedia (and thus CC-BY-SA which might also be problematic) and Project Gutenberg (Public Domain?).