The prophet and observer of the phenomena is Howard Rheingold, whose book "Smart Mobs: The Next Social Revolution," should be required reading for anyone wary of using technology to galvanize groups of people with or without motive, leader or ideology.
He cites President Joseph Estrada of the Philippines as the first head of state to be deposed by a flash mob. More than a million Manila residents, mobilized over four days by electronic text messages, pulled him down in 1999. Flash mobs were responsible for the Miss World riots in Nigeria that led to many deaths.
More than 400,000 young people in Brazil have joined a nebulous group called "Blah" to flirt with others clutching Palm Pilots, communicating in digital texts without knowing whether the persons they flirt with may be standing next to them (or miles away). Japanese teenagers walk down the street and through school hallways punching in text rather than talking. Adults can't hear them, and that's the point.
Flash mobs can be decentralized for political campaigns. Karl Rove used his Blackberry to dispatch Republican workers to get out the vote for George W. Bush. The anti-globalization folks use such devices for getting out their demonstrators.
Appropriately, Howard Rheingold was once editor of "The Whole Earth Review," a magazine offering " access to tools" to help people control their lives in the spirit of freedom and knowledge. His ideas go back to Emerson, the 19th century essayist who appealed to American "self-reliance."
He writes as skeptic, critic and defender of the potential inherent in the networks of emerging technologies.
"I have used the term 'smart mobs' he writes, "because I believe the time is right to combine conscious cooperation, the fun kind, with the unconscious reciprocal altruism that is rooted in our genes."
But the beneficial use of these technologies won't emerge unless we pay close attention to their dangers and opportunities.