When terrorists attack or natural disasters strike, smartphone users often function as on-the-spot reporters. The information and images they post online can protect others, but could also serve to spread panic.
These informal social media reporters can cause problems - especially for the police. They might spread false reports and complicate the work of first responders. And un-edited live images of the police at work could inadvertantly help perpetrators or reveal information. Images and videos on social media also tend to perpetuate the attackers' fame long after the fact.