As Deborah Cohan entered the operating room at San Francisco's Mt. Zion Hospital to undergo a double mastectomy, she would have been fully within her rights to go ballistic and throw stuff around.

Spain is in the midst of prolonged and devastating financial crisis. Its economy lost roughly 800,000 jobs last year, more than half of under-25-year-olds are unemployed, and the total unemployment rate is at 26% and growing. So you can imagine how bleak and hopeless people waiting (and working) in one of their umemployment offices might feel.

To promote local radio station Radio Klassisk, members of the Copenhagen Philharmonic Orchestra (Sjællands Symfoniorkester) treated Copenhagen Metro passengers to a flash-mob performance of Edvard Grieg's Peer Gynt.

Fresh Prince of Bel Air actor Alfonso Ribeiro was joined by hundreds of "Carlton Dancers" all across North America to perform his signature moves during a recent attempt to break the world record for the Largest Simultaneous Flash Mob.

At 3:15PM, Berlin time, The Wall Street Journal suffered an unprecedented attack, The Wall Street Journal reports. A shadowy organization called "Anonymous Kollektiv" had orchestrated a "comment flash mob." The chilling result: Facebook comments. Here is what they said:

The flash mob, once a novel and artistic construct used to make urban life that much more quirky and full of possibility, is now the subject of a Howie Mandel show. So it was only a matter of time before flash mobs degenerated into something ugly, violent, and antisocial. Yesterday, a shooting at Venice Beach sent crowds scattering. Why?

Toronto went off this weekend! The G-20 summit was held there, so some angry Canadians converged on the city to protest, burn and loot. Who are these violent anarchists? They came in from Quebec, naturally.

After a Twitter-driven teenage flash mob that scared grown-up Philadelphians shitless last week, local police are cracking down—but another mob may be forming now, tweets CNN's Don Lemon. Wait a minute, is Don Lemon starting a flash mob?

Flash mob tonight at 7:00 at Grand Central! It's a group of M.I.T. students assembling "in support of photographers' rights." So, kinda like that earlier flash mob at Grand Central where everyone froze, but not cool. [City Room]

The effort to invade some innocent wifi cafe continues. Tailrank creator Kevin Burton wants to run a "San Francisco Wifi Bedouin Flash Mob" (which would make a great electronica collective name). Basically, a couple dozen people descend on a wifi cafe, making a show of purchasing power and feeling trendy while doing so.