"A flash mob ... is a large group of people who assemble suddenly in a public place, perform an unusual action for a brief time, then quickly disperse." (Wikipedia.)

Beginning in 2003, flash mobs were a form of activity organised via mobile phones and internet; bringing contacts together in public spaces to act out various bizarre acts of collective non-conformity such as pillow fights, water pistol battles, silent discos (where earphoned individuals dance to their personal stereos/mp3 players) etc. Like short pieces of performance art, briefly changing the normal usage of public space and providing a safe thrill of 'non-corformity' expressed as a crowd all doing the same pre-defined activity. But now a trade union - not organisations normally noted for their innovation or imagination - has begun to use flash mobbing as an effective tactic during strikes.

The German trade union Verdi, with a membership of nearly two and a half million employees in the retail and public sectors, organized around 150 men and women to visit a shopping center in Aschersleben in the state of Saxony-Anhalt last week;

Quote:
The flash mob entered the shopping center and proceeded to load up shopping carts with an assortment of goods before simply leaving them standing in store aisles. Instead of paying for the goods, the flash mob passed over cards with slogans like "Fair Wages" and "Fair Means More." Business came to a stand still for about an hour and staff told reporters that it would take them all day to put the goods back on the shelves.

The protest had been organized as a result of disagreements over pay and conditions between Verdi and retail sector bosses in the states of Saxony-Anhalt, Thuringia and Saxony. "With this new form of strike we wanted to draw attention to our problems. But we also wanted to let our colleagues in other sales areas know about our problems," union secretary Doris Finke told local newspaper Mitteldeutsche Zeitung.
 http://www.spiegel.de/international/germany/0,1518,652867,00.html

Video here;  http://www.youtube.com/watch?v=nCJ6ZTSh19Y&feature=player_embedded

A largely peaceful event, one person was arrested in a scuffle with a security guard and a few others due to "damage to frozen goods" (presumably as they melted in shopping trolleys).

This flash mob occurred two days after a ruling by Germany's Federal Labor Court decided that flash mobs were a legitimate form of industrial action. The subject of this case was an earlier flash mob organised by Verdi in 2007;

Quote:
During the 2007 event, that lasted around an hour, approximately 40 protestors filled their shopping trolleys to the brim with the cheapest items they could find and caused huge queues in a supermarket in Berlin's Ostbahnhof station. The flash mobbers also left their shopping carts standing there. One woman, for instance, went through the checkout with about €300 worth of goods costing an euro or less but once the cashier had totaled up her purchases, the shopper said she had left her purse at home.

The idea for the 2007 flash mob came about after protacted pay negotiations ended in a deadlock, Erika Ritter of Verdi who is responsible for the retail sector in Berlin-Brandenburg told the newspaper Berliner Morgenpost newspaper. Work stoppages had not helped -- which was why they had come up with the idea for a flash mob-style action. It had had an immediate effect on negotiations, Ritter said, and Verdi would consider similar actions again in the future. "But only when conventional strikes have not had any effect," she noted. (Op. cit.)

Nils Busch-Petersen, the head of Berlin-Brandenburg Trade Association - who brought the case against the union - responded to their legal defeat with "This form of industrial action is intolerable". He plans to appeal the labor court's judgment on flash mobs. "We are still waiting for the court's grounds for making this judgment," Busch-Peterson said. "But the trend is clear: And we want to file a suit against flash mobs with the constitutional court."

Flash mobs have also recently been used by climate change activists. It will be interesting to see if this spreads more widely - it's a tactic that could easily be applied to struggles and workers' disputes in various retail outlets; such as self-service food restaurants, 'Homebase'-type DIY supplies warehouses, electrical goods etc.