DALLAS -- Before he gunned down a dozen Dallas police and transit officers -- killing five of them -- 25-year-old Micah Johnson was very active online.
His Facebook page was covered in black nationalist symbolism. It also shows that he visited and liked a multitude of African American groups that espouse more than just black awareness or empowerment, but hate and violence.
The African American Defense League is one of them. Shortly after news broke of a black man being killed in Baton Rouge last week, for example, the AADL posted, then deleted a call to arms, which said "...calling on the gangs across the nation! attack everything in blue..."
The postings led to a nationwide alert issued by the FBI Thursday -- warning all law enforcement that attacks on police were being called for.
"Certainly, they are putting out incendiary content and if someone who is inclined toward violence is reading that, they may fixate on that content as a reason to take action," says J.M. Berger, who studies extremist groups for the George Washington University.
He knows the FBI is monitoring sites like these, and while he says they haven't risen to the level of actual terrorists, he is troubled where these sites may be headed.
"So, you know, we don't see the same sort of enforcement against white nationalists and black nationalists that we see against jihadists groups, and that's probably going to be an impending problem for us," said Berger. "What we do see is that extremist groups of all types are getting on the internet more. They are exploiting the lessons that, can be learned from ISIS's success."
Almost like a page from the ISIS playbook, domestic hate sites have already started to make Micah Johnson a martyr.
Hate, which, as we've seen over the past few days, doesn't lead to anything good.