>Read between the lines.
https://www.voanews.com/a/fbi-task-force-sharing-information-about-online-trolls/4516728.html
https://www.thenation.com/article/the-fbi-is-setting-up-a-task-force-to-monitor-social-media/
I wonder if the FBI finds these vulnerable and unstable people for their school shooter program using this method. It's not perfect (far from) but most of the time it leads them to an ideal candidate based on their "online footprint." "Birds of a feather."