“Every time word spreads that Maricopa County Sheriff Joe Arpaio is conducting one of his controversial crime sweeps, Lydia Guzman drives to the scene to see for herself. The rumors often turn out to be false. But when they are true, Guzman, an advocate for immigrant and civil rights, springs into action, sending a wave of text messages to a wide network of contacts, who in turn forward the texts to their own contacts. Guzman is the trunk of a sophisticated texting tree designed to, within minutes, alert thousands of people throughout the Valley to the details of Arpaio’s crime sweeps, which critics contend are an excuse to round up illegal immigrants.” (01/03/10)