A US soldier has been accused of plotting an attack on his own unit by sending information to an obscure Nazi Satanist organisation called the Order of Nine Angles (ONA). But who are they?
Founded in the UK in the 1970s, the ONA is an increasing focus for law enforcement and has appeared as an influence in several recent UK terrorism prosecutions relating to the extreme right-wing.
The group lionises the Nazi era and dates its calendar from the birth of Adolf Hitler, but its supernatural belief system goes beyond anything normally associated with right-wing extremism.
Its short-term goal is to undermine what it caricatures as a decadent Judeo-Christian society, with an emphasis placed on real-world acts, the aim being a new imperial civilization based a cruel mixture of Social Darwinism, Satanism, and Fascism.
Adherents are encouraged to secretly infiltrate organisations such as the military or Christian churches in order to destabilise them from within.
Those who progress through the ONA's hierarchical ranks are required to undertake various tasks, including forming their own small groups to prove their leadership abilities, with the result that a decentralised network of associated bodies exists throughout various countries.
There is a total rejection of ethics and some key texts even discuss ritual sacrifice, both symbolic and actual.
Figures such as the British murderer Ian Brady are celebrated, being viewed as people who have operated outside normal moral boundaries - the transgression of which is a constant theme for the group.
One small US-based associate body - which has its own publishing house - was banned from mainstream social media last year. Its members had posed at the sites of various notorious rapes and murders, celebrating the perpetrators in the process.
Some followers also express enthusiasm for Islamist jihadist violence.
All this real-world activity is supposed to have a supernatural effect, opening up a gateway into the world for evil energies.
The ONA has acted as an influence on several neo-Nazi extremist groups, including the US-based Atomwaffen Division - linked to five murders - and the Sonnenkrieg Division, which was banned as a terrorist organisation in the UK earlier this year.
Such groups reject attempts at gaining popular support for the extreme right - whether through demonstrations or campaigns - and are instead committed to an ideology of so-called accelerationism, which predicts societal collapse and racial warfare, seeking to speed the process up through acts of violence.
The ideology is promoted in several online spaces and that is where it has blended with the ideas promoted by ONA, giving the latter an increased influence on the furthest edges of the extreme right.
The Durham teen neo-Nazi who became 'living dead'
Last year a 16-year-old British boy became the youngest person convicted of planning a terror attack in the UK.
The prosecution's case was that he was partly influenced by the ONA, seeking to alter himself in line with their literature.
He had drawn a symbol for the group alongside an instruction for himself to "shed empathy".
In court, prosecutors described the organisation as "self-consciously, explicitly malevolent" and the "most prominent and recognisable link between Satanism and the extreme right".
The Sonnenkrieg Division, with its glorification of sexual violence, highlights another disturbing theme relating to the ONA - sexual offending as a way of undermining social norms.
The US soldier charged in the terrorism case is alleged to have been part of an online movement whose channels constantly encourage the rape of women and children
The authorities are concerned by the number of paedophiles associated with the ONA, taking the group into a different area of law enforcement activity.