Why messaging could be murder in Jamaica
26 February 2013 Last updated at 03:20 GMT
We all know about the dangers of texting while driving. But police in Jamaica are warning about a different threat posed by mobile phone use.
Motorists on the Caribbean island are using free messaging services such as Blackberry Messenger and Whatsapp to alert large numbers of people when they see police roadblocks.
The random checks have been used by police to help catch gang members and criminals carrying guns unaware.
The murder rate in Jamaica has dropped 35% since its peak in 2009, but more than 1,000 people are killed each year, making it one of the most violent countries in the world.
The BBC's Jamaica correspondent Nick Davis reports.