During the summer of 2016, Santiago Aguirre divided his time between part-time university lecturing and working for an organization that helps locate missing people. Mexico was then in the news internationally because of presidential candidate Donald Trump’s promise to build a wall on the American border with its southern neighbor. However, for Aguirre, a Mexican human rights activist, the problems of the present were far more pressing than any future wall. At the time, he was in the midst of a lengthy investigation to solve the mystery of the disappearance and presumed murder of 43 students in the city of Iguala two years before. It was becoming increasingly clear that his findings were incompatible with the results of the investigation conducted by the government.

Aguirre wasn’t concerned when he received a series of text messages containing broken links. “Please help me with my brother, the police took him only because he is a teacher,” one message read. And another: “Professor, I encountered a problem. I am sending back my thesis, which is based on your dissertation, so that you can give me your comments.” The messages looked no different from many of the legitimate messages he received every day as part of his work. And therein lay the secret of their power. When Aguirre clicked on the links, however, he was inadvertently turning his smartphone into a surveillance device in the hands of the government.

“Those text messages had information that was personal,” Aguirre notes, “the kind of information that could make the message interesting for me so I would click. It wasn’t until later that I actually thought – well, it is actually pretty weird that I received three messages with broken links.”

The discovery had a brutally chilling effect on the work of his organization. For the first time, he says, speaking with Haaretz by phone, he really and truly feared that every step he took was being watched, and that perhaps his family too was under surveillance. Read more via Haaretz