Below are adapted excerpts from the profile of 'Marco Jacobs' at the former Undercover Research Group wiki, last updated in 2018. Since then a civil case has been resolved regarding EN1, with the claimants receiving a financial settlement.
EN1 ‘Marco Jacobs’ first appeared in Brighton in late 2004, and quickly made attempts to inveigle his way into political groups, primarily those of a direct action-oriented anarchist or anti-authoritarian nature, including SMASH EDO. He attended local protests, travelled to demonstrations in other parts of the country, took part in meetings, and socialised with activists.
However, it appears that he was never entirely trusted within the Brighton activist community. In 2005 he moved to Cardiff, where he repeated the same repertoire of behaviour, but, it seems, more successfully. He spied upon campaigns involving the Cardiff Anarchist Network and South Wales Anarchist groups. Howver, he also targeted the Camp for Climate Action and the No Borders network.
He had two sexual relationships in his cover identity and was involved in planning a direct action for which he was arrested for but not convicted.