A shooting spree by a lone gunman took place across three small towns in the English county of Cumbria on 6/2.
http://news.bbc.co.uk/2/hi/uk_news/england/10229099.stm

The media has already begun looking at the role social media played in this event. http://www.timesonline.co.uk/tol/news/uk/crime/article7142639.ece

It can be expected that this incident will force local and national authorities to examine how effective current alerting methods were in protecting the public during this event, and how they can be improved in the future. A rapid mobile alerting campaign may have been critical in avoiding casualties.