When asked, a speaker of the ARD Programmdirektion told the Protestant news agency idea that the change of programme had "legal reasons". Instead of the cancelled documentary, a less controversial feature about young mothers was broadcast: "Zu jung für ein Kind? – Wenn Jugendliche Mütter werden" (Too Young for a Child - When Adolescents Become Mothers).
The ARD had announced the documentary at their website:
"Murder, land-grabbing, rape and violence in the middle of the street. For about ten years now, Islamic fundamentalists are terrorising Bethlehem's Christian population. A minority without defence. The PA and their security watch are watching without doing a thing. Samir Qumsieh, human rights activist and owner of a small TV station has collected more than 140 cases of terror against Christians... "The text and the lead to the documentary "Terror gegen Christen" has been deleted in the meantime from the ARD webpage.
(Hat-tip for Eurient!)