This is a good article on how Somalia's al-Shabaab militant group who attacked a shopping mall in Nairobi used Twitter to broadcast their goals. I never heard about this on the local news. But you did hear on how local were using Twitter and Facebook and there cells to talk or commincate with love ones. The same thing happen with the LAX shooting two weeks ago.
http://online.wsj.com/news/articles/...91720477473610