There’s a growth industry in trying to measure social media’s impact on our lives — and politics. Many argue that online political activism is superficial engagement, lacking the personal ties of community that once drove social change. Social media’s evangelists demur, declaring that a new code of politics is being written online, altering the political commons but making us more socially connected than ever before. The articles here ask whether the phenomenon of disintegrating social connections Harvard political scientist Robert Putnam described as “bowling alone” still prevails in the digital age, or whether social media activism — call it “bowling online” — harbours the power to strengthen democracy.