Why cellphone chats have become death sentences in cartel stronghold in Mexico

Cellphone chats have become death sentences in the continuing, bloody factional war inside Mexico's Sinaloa drug cartel.

Cartel gunmen stop youths on the street or in their cars and demand their phones. If they find a contact who's a member of a rival faction, a chat with a wrong word or a photo with the wrong person, the phone owner is dead.

Then, they'll go after everyone on that person's contact list, forming a potential chain of kidnapping, torture and death. That has left residents of Culiacan, the capital of Sinaloa state, afraid to even leave home at night, much less visit towns a few miles away where many have weekend retreats.