DGG is one of the members of Wikipedia's Arbitration Committee who banned our editor Coat of Many Colours following a complaint by the Wikipedia editor Hafspajen that Coat was hacking Hafspajen's computer. Hafspajen later claimed that it was Wikipedia itself that was hacking her computer. The issue was investigated by Wikipedia and no evidence was found to suggest that Hafspajen's account had been compromised. Hafspajen nevertheless continued to maintain that Wikipedia was hacking her computer and ceased editing at the beginning of the year (2016).
DGG self identifies on his user page as David Goodman, a librarian. Edit stats conducted mid-April 2016 show that DGG has made some 200,000 Wikipedia edits over a ten year period. About a third of these (33%) are in article space and for the most part are related to information science and similar topics. We are not aware that DGG has been singled out for any special opprobium regarding his various duties as a Wikipedia functionary. There is a Wikipediocracy thread referencing him here, but it concerns an internal affair of that forum and is not especially notable.