The social-media platform isn’t a public square. It’s a gladiatorial arena.

Facebook’s Libra would be free to use and free to roam, changing hands and crossing borders costlessly or nearly costlessly.

A new graphical warning system

Opioid addicts are turning to online forums for advice about quitting. Their conversations have a lot to teach us about drug use and public health.

The intelligence-leak suspect allegedly wanted to show off online.

People must be willing to defend it.