Susan Etlinger promotes the smart, well-considered and ethical use of data.

Toby Eccles has created a radical financial instrument that helps private investors contribute to solving thorny public problems.

As the director of the Human-Computer Interaction Lab at the University of Maryland, Jennifer Golbeck studies how people use social media -- and thinks about ways to improve their interactions.

Sociologist and philosopher Renata Salecl scrutinizes our individual and societal neuroses, and suggests ways out of our current paralysis.

Courtney E. Martin’s work has two obsessions at its core: storytelling and solutions.

Sarah Corbett does activism in a quiet, humble and intriguing way using handicrafts.

Sometimes controversial, always practical ethicist Peter Singer stirs public debate about morality, from animal welfare to global poverty.

Mundano's bold, colorful street art isn't just eye candy. His projects call attention to social, environmental and political issues, while raising chuckles from passersby.

Techno-sociologist Zeynep Tufekci asks big questions about our societies and our lives, as both algorithms and digital connectivity spread.

As editor in chief at Mashable, Adam Ostrow covers the tech, trends and people driving the evolution of the Web.

Del Harvey works to define policy and to ensure user safety and security in the challenging realm of modern social media.

Ken Goldberg works reflect the intersection of robotics, social media, and art.

Sethembile Msezane deconstructs the act of public commemoration -- how it creates myths, constructs histories, includes some and excludes others.

Caroline Casey works relentlessly to bring out a global shift in business inclusion, and ensure that everyone can live their life without limit or labels.

What motivates you to share your personal information online? Alessandro Acquisti studies the behavioral economics of privacy (and information security) in social networks.

Lisa Gansky is the author of "The Mesh: Why the Future of Business Is Sharing," and the instigator behind the Mesh Directory (www.meshing.it).

JD Schramm teaches future business leaders both the theoretical and practical aspects of communication.

Mark Raymond’s work as an architect in Trinidad and Tobago is founded on the belief that thoughtfully designed cities can foster sustainability and inclusiveness throughout a society.

A humanist in Silicon Valley, Tim Leberecht argues that in a time of artificial intelligence, big data and the quantification of everything, we are losing sight of the importance of the emotional and social aspects of our work.

Prison reform advocate Ismael Nazario helps former inmates from New York's Rikers Island jail reenter society.

Clay Shirky argues that the history of the modern world could be rendered as the history of ways of arguing, where changes in media change what sort of arguments are possible -- with deep social and political implications.

Wael Ghonim believes that the Internet can be the most powerful platform for connecting humanity, if we can bring civility and thoughtful conversations back to it.

Evan Williams is the co-founder of Twitter, the addictive messaging service that connects the world 140 characters at a time.

Evgeny Morozov wants to know how the Internet has changed the conduct of global affairs, because it certainly has ... but perhaps not in all the ways we think.

Monica Lewinsky advocates for a safer and more compassionate social media environment, drawing from her unique experiences at the epicenter of a media maelstrom in 1998.

Jim Yong Kim is leading a global effort to end extreme poverty and promote shared prosperity.

LaToya Ruby Frazier focuses her camera lens on working class families, exploring themes of family, inequality, health care and environmental racism.

Laura Snyder weaves tales of Victorian-era scientists that have been described as “fit for Masterpiece Theater.”

James Surowiecki argues that people, when we act en masse, are smarter than we think. He's the author of The Wisdom of Crowds and writes about finance for the New Yorker.

The founder of the Riverside School in Ahmedabad, Kiran Sethi has launched an initiative to make our cities more child-friendly.