Disruptions: Indiscreet Photos, Glimpsed Then Gone

By NICK BILTON

Snapchat allows people to take and send a picture, then control how long it is visible by the person who receives it.

People once took photographs so they could capture a moment for themselves and keep it forever. Then digital cameras and cellphones turned photos into something more ephemeral and more easily shared. But as the case of Anthony Weiner demonstrated, photos that are shared but are not meant to last, sometimes stick around.