This blog has a strap line "crime, fear and mapping"; these maps probably contain the most fear and crime that I have seen. There is a terrible turf war going on in Mexico over drugs, mostly to do with the battle over who is going to control the the export market to the USA. The top map is recent and the lower one dates back to just before the leader of the Beltran Levya gang was killed in a shotout against at least 200 army personal around Christmas 2009.
I post the maps today because of this story. You can learn more about the ongoing saga of murder and mayhem by following the links on the BBC website. This is the one I found most distressing and this the most shocking.