Received anonymously:

Conscious of the fact that Telmex destroys the land and sponsors bull-torturing events, we of the Brigades for the Liberation of Colima, Mexico have sabotaged over 30 phones in just 2 days.
Sabotage is easy, take action.

Spanish:
Concientes de que Telmex destruye la tierra y patrosina actos para torturar toros, las Brigadas por la Liberacion de Colima Mexico, hemos saboteado mas de 30 telefonos en tan solo 2 dias.
El sabotaje es facil, llevalo a cabo.