Catherine Crump: The small and surprisingly dangerous detail the police track about you

A very unsexy-sounding piece of technology could mean that the police know where you go, with whom, and when: the automatic license plate reader. These cameras are innocuously placed all across small-town America to catch known criminals, but as lawyer and TED Fellow Catherine Crump shows, the data they collect in aggregate could have disastrous consequences for everyone the world over.

Boniface Mwangi: The day I stood up alone

Photographer Boniface Mwangi wanted to protest against corruption in his home country of Kenya. So he made a plan: He and some friends would stand up and heckle during a public mass meeting. But when the moment came … he stood alone. What happened next, he says, showed him who he truly was. As he says, “There are two most powerful days in your life. The day you are born, and the day you discover why.” Graphic images.

The Lady Lifers: A moving song from women in prison for life

The ten women in this chorus have all been sentenced to life in prison. They share a moving song about their experiences — one that reveals their hopes, regrets and fears. “I’m not an angel,” sings one, “but I’m not the devil.” Filmed at an independent TEDx event inside Muncy State Prison, it’s a rare and poignant look inside the world of people imprisoned with no hope of parole. (Note: The prison’s Office of Victim Advocacy has ensured that victims were treated fairly and respectfully around this TEDx event.)

Romina Libster: The power of herd immunity

How do vaccines prevent disease — even among people too young to get vaccinated? It’s a concept called “herd immunity,” and it relies on a critical mass of people getting their shots to break the chain of infection. Health researcher Romina Libster shows how herd immunity contained a deadly outbreak of H1N1 in her hometown. (In Spanish with subtitles.)

Ilona Szabó de Carvalho: 4 lessons I learned from taking a stand against drugs and gun violence

Throughout her career in banking Ilona Szabó de Carvalho never imagined she’d someday start a social movement. But living in her native Brazil, which leads the world in homicidal violence, she realized she couldn’t just stand by and watch drugs and guns tear her country apart. Szabó de Carvalho reveals four crucial lessons she learned when she left her cushy job and took a fearless stand against the status quo.