For four years, police infiltrated the London chapter of the International Solidarity Movement, an activist group focused on Palestine.
Using the cover name Rob Harrison, one ISM activist was actually a member of the Special Demonstration Squad, information released by a UK government inquiry this week shows.
ISM volunteers, mostly from European and North American countries, join non-violent solidarity activities in Palestine, such as protests, accompaniment and olive picking.
ISM volunteers Rachel Corrie and Tom Hurndall were both killed after being fatally wounded by Israeli occupation forces in 2003.
ISM London ran sessions around the UK training volunteers on what to expect in Palestine and how to join the group there.
That the British government is calling up 3,500 armed troops to be on standby, is very frightening indeed.