I think it refers to this: https://drive.google.com/file/d/1M6PMQrehmeuRU_KDd_PTKsTtVNN...

It doesn't seem very convincing in its conclusions, but has some interesting information nonetheless. I searched for some info on this doc, and it seems that its author really did hire some private investigators, I even found gofundme for it and places where the author asked for help in the early stages of their investigation. It seems they were trying to find the website owner because he hadn’t responded to requests to delete some personal things archived by a prolific stalker.