In short, Trader Joe's doesn't have any connection to the giant chain that actually operates in Germany. And while it's possible that the grocer's corporate cousins elsewhere in Europe source from Spain's environmentally troublesome greenhouses (some of the stores are in Spain, after all), we don't know for sure.
"I hear what you're saying about Trader Joe's and Aldi," Caldwell said, after I suggested the link between the two might be somewhat weak. "For us, the connection is very strong. If the U.S., which is one of Aldi's biggest markets—if Trader Joe's was sending the message back to Aldi's headquarters in Germany saying, 'We're coming under a lot of pressure from our consumers to make sure that we as a whole group are doing something about this issue,' then they will respond very quickly."
419,000 people had signed the petition as of last Sunday, when Caldwell and I spoke, and it's soon to be the most popular petition on SumOfUs.org since the site's launch two years ago.
I asked Caldwell if there was any other way to put pressure on the greenhouse growers directly, instead of the grocers. "It would essentially be through governmental action," he said. "And with such an important industry like there is in Southern Spain, the government, particularly given their economic issues at the moment, they're unlikely to be intruding very heavily with extra regulation.
"One of the things that makes SumOfUs so unique," he continued, "is that we can mobilize that global consumer opinion that sometimes is lacking. Where governments are played against each other by corporations, we can come in and pressure the bottom line."
Perhaps. But it still seems a bit disingenuous to single out a mostly tangential player in the supply chain, like Trader Joe's, in order to drum up publicity on this issue.
A whale that died from eating plastic is a symbol of devastating ocean pollution—and that's an issue that truly deserves more attention from everyone—but it's surprising that this is provoking more ire than the other dirty secret of the Spanish greenhouse growers: the illegal and exploitative use of labor from African immigrants. Australian journalist Eric Ellis has compared the working conditions in the "sea of plastic," as the greenhouse network is known, to the cotton plantations in America's Deep South in the era of slavery.* Guardian reporter Felicity Lawrence authored a scathing investigative report in 2011, which described workers relying on Red Cross food parcel deliveries and living among the "hothouses" without reliable sources of drinking water.
"We haven't looked at that specific issue," Caldwell said, when I asked if there might be a future petition on behalf of the exploited workers, "but it goes to such a wider problem in terms of industrialized agriculture on this kind of scale. Not only in terms of its environmental impact... but also on human beings who are sucked into this hard, hard labor to supply Western European consumers with... you know, year-round lettuce."
Indeed. But for now, SumOfUs is busy prodding a grocery store that may or may not be connected to the death of a single whale.
*An earlier version of this article identified Eric Ellis as a British journalist. He is, in fact, Australian.