Source: ZD Net – Zack Whittaker
"With experience of hindsight, with a number of events which social networking from ordinary members of the public (”citizen journalism”) from the terrorist attacks in Mumbai, the Hudson river plane crash and the death of Michael Jackson; Twitter especially has been a key point of communication.
"Twitter is instant and is accessible from anywhere with mobile signal. However the big issue with the London bombings is that the explosions were underground, some closer to Tube stations than others, but most had no signal while they were down there. Yet videos and texts were still sent to be delivered as soon as a trailing signal came into focus when they reached the surface."