IN EARLY 2012, Marie Colvin, an acclaimed international journalist from New York, entered the besieged city of Homs, Syria, while reporting for London's Sunday Times. She wrote of a difficult journey involving "a smugglers' route, which I promised not to reveal, climbing over walls in the dark and slipping into muddy trenches." Despite the covert approach, Syrian forces still managed to get to Colvin; under orders to "kill any journalist that set foot on Syrian soil," they bombed the makeshift media center she was working in, killing her and one other journalist and injuring two others. Syrian forces may have found Colvin by tracing her phone, according to a lawsuit filed by Colvin's family this month. Syrian military intelligence used "signal interception devices to monitor satellite dish and cellphone communications and trace journalists' locations," the suit says. In dangerous environments like war-torn Syria, smartphones become indispensable tools for journalists, human rights