Fusion GPS was founded by journalists, who as such were trained, professional libelers. (They worked for the Wall Street Journal). I don’t know if they were laid off or just got smart and realized they could do the same work for the WSJ for peanuts or operate their own shop and make megabucks from scoundrels. Much easier than selling papers.
In the Hannity interview Thor mentioned after he went after the 4 guys who got rich ripping off Venezuela they asked to talk with him. It was his old boss from the Wall Street Journal who was there with the 4 to get him to crush his story!