It is of continuous disappointment to me that there really isn't not only a good FOSS link-analysis tool, but doesn't appear to be any of any quality. I've used yED in a pinch a couple of times but it's not FOSS.
Governments and police in particular are customers for these tools and they do care about open source. If there was a good competitive FOSS tool out there, not a weekend project by any means, but a serious effort. It would be adopted.
Plenty of folks in the DEFCON crowd could be building free tools like this; off the cuff, a lot of anti-fascists probably don't have access to high quality OSINT analysis tools, and certainly aren't persuing Palantir contracts.