Summary Box: Urgent tweet in Kenya village

CRIME-FIGHTING TWEETS: In Kenya, Francis Kariuki is trying to improve village life by regularly sending out tweets about missing children and farm animals.

REMOTE LOCATION: This shows that the power of social media has reached even into a dusty African village, Lanet Umoja, which is 100 miles west of the capital, Nairobi.

MULTIPYING EFFECT: Although the official Twitter page shows 300 followers, Kariuki estimates that thousands receive the messages he sends out directly and indirectly. Many access tweets through a third-party mobile phone application. Others forward the tweets via text message.