Vigilant was known to Wikipedia users as Vigilant~enwiki for two months in 2006, and he spent most of his time fighting with Jeff Merkey (Waya sahoni and Sint Holo.) Merkey would become an obsession over the next ten years. Merkey worked for Novell, considered himself of partial Native American descent (thus the names for his sockpuppets), was banned from Wikipedia, and was chased off Wikipedia Review by Vigilant when that messageboard was still viable. (Jeff Merkey also likes to sue anybody who criticizes him online.) Merkey thought his antagonist was actually Paul Hands, but he also mentioned "Al Petrofsky" by name. That, by the way, is the same version of Petrofsky's first name used on the SCOfacts website, which also has a page on Merkey. There is also a page on the legal dealings of Eclipse Aviation, which was this light aviation company run by an ex-Microsoft employee. The firm lasted from 1998 to 2009, but that Petrofsky website dates to 2008. All of the websites run by Petrofsky were about legal cases, with SCOfacts dealing in the lawsuits run by a UNIX software manufacturer who decided to sue as many Linux vendors and users as humanly possible and they were bankrupt by 2009-ish.
The thing that sticks out with that Eclipse Aviation legal blog is that there may be a link to Wikipedia through the user name Ahunt, who writes tons of entries on civil aviation topics. Is Vigilant also Ahunt? Are both of them Petrofsky? Or neither? There is a belief I've been told that Vigilant is actually using Wikipedia as a search engine optimization linkfarm like Jehochman allegedly did. On Wikipediocracy's messageboard there are only two long-time members where the true names are not known: Tarantino and Vigilant. We will probably never know who they are.
A possible Petrofsky-written blog post from 2005.
A Jeff Merkey lawsuit.
A Czech guy on the Merkey-Petrofsky fights.
A PDF of a 2005 lawsuit.
[Postscript: We forgot to mention the "SCOX" Yahoo group where Petrofsky was a member (or "Demon" as they were known) in 2003-2004. The Yahoo archive of that group has since vanished.]