Records also indicated that this cell phone had communicated with only one other telephone—the one that Cardona Medina had reported receiving from the Valdés Paiz brothers.

One night last week, Ryan Cassidy, an 18-year-old recent high school graduate, began playing Xbox at 10:30 p.m., using two-minute breaks within the game to play another game on his cell phone.

Medicall Home, a Mexican outfit that provides medical consultations by mobile, already has millions of customers.