The third sentence further explains the false spontaneity: "In operations that contingency planners term 'controlled spontaneity', politicians’ statements, vigils and inter-faith events are also negotiated and planned in readiness for any terrorist attack."

Basically: the UK government coordinates social media campaigns to promote social cohesion in the wake of terror attacks, and additionally coordinates with community leaders and politicians. That's all you can draw from the article, unless you have additional information or sources to the contrary.