gb2260 is copyright 2014–2017 Paul Natsuo Kishimoto and distributed under the GNU GPLv3.
The NBS website, which is scraped as the main and authoritative source of data, provides this copyright statement.
gbt_2260-2007.csv and gbt_2260-2007_sup.csv contain transcribed information from GB/T 2260-2007, the copyright of which is unknown.
citas.csv is under the following "use constraints" (with emphasis added):
The University of Washington China in Time and Space (CITAS), Chinese Academy of Surveying and Mapping (CASM), and Trustees of Columbia University in the City of New York hold the copyright of this data set. Users are prohibited from any commercial, non-free resale, or redistribution without explicit written permission from CITAS, CASM, and CIESIN. Users should acknowledge CITAS, CASM, and CIESIN as the source used in the creation of any reports, publications, new data sets, derived products, or services resulting from the use of this data set. CITAS, CASM, and CIESIN also request reprints of any publications and notification of any redistributing efforts