From the NYTimes article noted in the cited article...
www.nytimes.com

... No Lives Matter is a nihilistic, far-right ideology that largely exists on encrypted online messaging apps like Telegram.

The movement's adherents promote "targeted attacks, mass killings and criminal activity" and have "historically encouraged members to engage in self-harm and animal abuse," according to a threat assessment released in August by the New Jersey Office of Homeland Security and Preparedness.

Prosecutors in Federal District Court in Norfolk filed the court papers describing Mr. Spafford's explosives in an effort to keep him in custody as his case moves toward trial. ...