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Opinion: ‘Swarm theft’ plaguing upscale stores

They descended in Montana, swept across the northern plains, and into Minnesota. Acre after acre, mile after mile, they spread through Iowa, Missouri, Nebraska, Kansas, Oklahoma, and Texas. It was a swarm unknown in human history. Their number was estimated to be in the trillions; their weight in excess of 27 million tons.

The year was 1874, and nearly everything in the farmlands and on ranches was lost: sawdust, leather, and even the clothes on people’s backs. They consumed wheat, barley, potatoes, beans, fruit trees, melons, strawberries, and tobacco. A historian in St. Louis, Missouri, wrote, “One farmer south of this city had fifteen acres of corn eaten by them yesterday in three hours. They mowed it down close to the ground as if a mowing machine had cut it.”

“They” are locusts. Basically, a locust is a grasshopper that experiences a “switch” in development. According to Rick Overton of Arizona State University’s Global Locust Initiative, most of the time the grasshopper leads a solitary life. It is generally overlooked as an unremarkable creature. He says, “Nobody really notices them.”

Phenotypic plasticity

For years, locusts can live like this, biding their time. But, under certain conditions, he says, “They increase in numbers, and as they do so, they sense one another around them.” Biologists call this the “gregarious phase” of the locust. Overton told Pranav Baskar of NPR, “They change their physiology. Their brain changes, their coloration changes, their body size changes. Instead of repelling one another, they become attracted to one another.” He elaborated that “…they start to march together in coordinated formations across the landscape….”

This dramatic change is called “phenotypic plasticity,” and nobody knows for sure why it occurs. The locust, like the solitary grasshopper, lives in a harsh environment. Overton says the strongest hypothesis is that these crazy, unpredictable dynamics occur as the creatures respond when (they) can capitalize on a rare opportunity to migrate in masse and gorge themselves on food.

Criminal plasticity

On Friday night, Nov. 19, 2021, mobs of thieves ransacked a number of high-end retailers in San Francisco’s Union Square. At the time of this writing, there have been no estimates as to the extent of damage caused or the value of items that were stolen. Two cars and two guns were seized by police, and merchants in and around the Bay Area were put on alert.

It appears that these mobs were not acting independently. Several mobs arrived at Union Square at the same time, they exhibited similar styles of theft, they departed together, and they tended to hit mostly high-end retailers.

According the KPIX (CBS News), the stores that were robbed and vandalized included Louis Vuitton, The Burberry, Yves Saint Laurent, and Bloomingdales, as well as Jin’s eyeglasses, Maxferd Jewelry & Loan, and others.

Of the dozens of people who engaged in the illegal and very dangerous behavior, eight have been arrested. According to Police Chief Bill Scott, most of those in custody are young adults. He said of the “flash mob” criminal event, “It was concerted. There’s no doubt in my mind that this was not unplanned.” He is confident that there will be more arrests because, “We have hours and hours of video — including our body-worn-camera videos — to go through.”


The plague of theft, like a swarm of locusts, seems to migrate from opportunity to opportunity. While the weekend invasion seemed to originate in San Francisco, the following day thieves swooped down on Walnut Creek, a city about 20 miles north of the City by the Bay.

According to Yahoo News, “On Saturday night, dozens of looters swarmed into the Nordstrom store in downtown Walnut Creek, terrorizing shoppers, assaulting employees, ripping off bag loads of merchandise and ransacking shelves before fleeing in several vehicles waiting for them on the street.”

Police Lieutenant Ryan Hibbs said that there were about 80 people who ran into the store and started looting and smashing shelves. According to CNN, the suspects arrived and fled in about 25 cars that jammed the street in Broadway Plaza, an outdoor mall. He told CBS that three people were in custody and being questioned to determine the identity of others who were being sought.

Brett Barrette, manager of P.F. Chang’s restaurant, which is located directly across the street from Nordstrom, watched as the drama unfolded. He told Yahoo News, “I probably saw 50-80 people in, like, ski masks with crowbars, a bunch of weapons. They were looting the Nordstrom. There was a mob of people. The police were flying in. It was like a scene out of a movie. It was insane.”

Looters struck again on Sunday evening, hitting a mall in Hayward, on the east side of the San Francisco Bay. It was the third day in a row that a swarm invaded retailers in the area. Thieves hit Sam’s Jewelers, and videos show people breaking glass cases and workers screaming in fear.

Witnesses said that this was actually the tail end of “a much scarier and bigger scene” in which other stores were robbed and vandalized. One witness said, “We saw all the other stores closing. They were panicking, so we were panicking. It was very scary. People with no morals, no sense for other people’s safety. I feel helpless. It’s disturbing.”

So far, no connection has been made among the mass-looting incidents in San Francisco, Walnut Creek, and Hayward. And similar crimes have been noted in San Jose and multiple cannabis dispensaries in Oakland.

Swarm theft

So far, the media are calling events like this “grab-and-go” robberies or “flash mob” acts of vandalism. I prefer my own term, “swarm theft” because the thieves swarm in like locusts and seem to have no plan for the future except to move on to the next target. Like locusts, they take anything and everything, and they seem to move in harmony like swarming insects — acting solely on a kind of criminal plasticity — void of any moral compass.

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Jim Glynn, Professor Emeritus of Sociology, may be contacted at

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