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While Amazon is working to push its big Prime Day summer sale this week, activists and unions are using the day to highlight their many concerns about the world's biggest online store. Their concerns vary widely, from working conditions in warehouses to climate issues to its ties to the US Immigration and Customs Enforcement agency.

Much of the activist attention in the US was directed at Shakopee, Minnesota, where Amazon warehouse workers protested Monday, in the middle of the Prime Day sale. They wanted to raise awareness to what they describe as poor working conditions and a lack of career advancement for the warehouse's many East African employees.

Those workers were joined by tech workers from Amazon Employees For Climate Justice, a group pushing Amazon to address climate issues, who flew in from Seattle to walk the picket line.

Other activities took place in New York, Seattle, San Francisco and Europe, according to organizers.

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The protests highlight how big tech companies like Amazon are facing considerably more pressure from public groups and their own employees over their business practices, worker treatment and partnerships. Google, for instance, has faced several employee protests for its handling of alleged sexual assault and misconduct, as well as Dragonfly, a company project to build a censored search engine for China.

Amazon similarly weathered a bevy of protesters during its May shareholder meeting in Seattle, where concerns were raised about the e-commerce giant's work on the climate as well as its facial recognition technology. The company has repeatedly defended itself against claims of worker mistreatment, saying it provides safe working conditions for its warehouse employees and offers a comprehensive package of benefits.

Amazon workers in the US aren't unionized, resulting in many of these organizations calling for more union representation and worker protections for those employees.

An Amazon spokesperson said Monday that if unions and politicians want to help American workers, they could work on passing legislation to increase the federal minimum wage of $7.25 an hour.

"Events like Prime Day have become an opportunity for our critics, including unions, to raise awareness for their cause, in this case, increased membership dues," the spokesperson said in a statement. "These groups are conjuring misinformation to work in their favor, when in fact we already offer the things they purport to be their cause -- industry leading pay of $15 per hour, benefits and a safe workplace for our employees."

The spokesperson said later Monday that roughly 15 Amazon workers participated in the strike. "It was obvious to the 1,500 full-time workforce that an outside organization used Prime Day to raise its own visibility," Amazon said. The Awood Center, a worker advocacy group, has helped organize several protests over the past year at Amazon's Minnesota warehouses, including the Prime Day rally.

A coalition of New York activist groups and immigrant families on Monday planned to deliver a petition to Amazon CEO Jeff Bezos' new Manhattan home, calling for an end to the company's work with ICE, which has faced criticism over its treatment of undocumented immigrants. Protesters against Amazon working with ICE rallied outside the company's AWS Summit in New York last week, too.

According to public records, Amazon has marketed its services to ICE. But, the company hasn't publicly confirmed it works with the federal agency, saying it doesn't mention customers unless they approve the disclosure. In an Amazon Web Services statement offered Monday, the company gave its general perspective on government using tech without addressing whether it works with ICE.

"As we've said many times and continue to believe strongly, companies and government organizations need to use existing and new technology responsibly and lawfully," an AWS spokesperson said. "There is clearly a need for more clarity from governments on what is acceptable use of AI and ramifications for its misuse, and we've provided a proposed legislative framework for this."

The New York coalition included Make the Road New York and ALIGN NY, two groups involved in protesting Amazon's failed HQ2 corporate office project in Queens. Other "No Tech 4 ICE" protests were slated for Seattle and San Francisco, Daily Kos reported.

In Europe, UNI Global Union, which has staged several Amazon protests during major shopping holidays like Black Friday, said it helped coordinate protests in Germany, the UK, Spain and Poland during Prime Day.

Supporters of the Shakopee protest included elected officials and airline pilots who fly for Amazon but aren't employees of the company, according to the Awood Center.

Additionally, Muslim Advocates, a civil rights group, and the United Food and Commercial Workers International Union, a regular critic of Amazon, expressed their support.

"Amazon workers are sending a powerful message to Jeff Bezos this Prime Day: It's time to stop putting profits ahead of people," UFCW President Marc Perrone said in a statement Monday. "With the recent move to one-day Prime shipping, Amazon workers are being forced to meet impossible demands at increasingly unsafe speeds."

An Amazon spokesperson said last week that it already offers what is being asked for in Shakopee, mentioning its pay and benefits package, which includes paid education, parental leave and promotional opportunities. Also, Amazon said last week it will spend over $700 million to help retrain 100,000 of its US workers for more technical and higher-demand jobs. Amazon last year raised its minimum wage to $15 an hour.

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"We encourage anyone to compare our pay, benefits and workplace to other retailers and major employers in the Shakopee community and across the country -- and we invite anyone to see for themselves by taking a tour of the facility," the company spokesperson said last week.

At the New York rally Monday afternoon, a group of hundreds of protesters gathered at Madison Square Park and walked down the street to Bezos' new home, where he reportedly purchased three apartments, including the penthouse, for $80 million. Outside the building, people chanted and waved signs that included "Stop Amazon-enabled surveillance of immigrant communities" and "Alexa, why is Amazon enabling ICE?!?"

In the crowd, Ko Takasugi-Czernowin, 23, held up a sign saying "Fuck Amazon's techno-dystopia." He said the company's support of ICE accelerates family separations and deportations. He said he canceled his Prime membership awhile ago and would not participant in Prime Day.

"Jeff Bezos is making all this money off this suffering," he said.

Rebecca Heinegg, 36, a lawyer who joined the Jews for Racial and Economic Justice group in the protest, said: "Today is Prime Day and so today is the day when they're trying to make a lot of noise of their brand. So we're trying to make a lot of noise about what they're enabling."

Dhara Singh contributed to this story.

First published July 15, 7:29 a.m. PT.

Updates, 8:50 a.m., 12:41 p.m. and 5:11 p.m. PT: Adds Amazon and AWS statements, as well as comments from the New York protest. Correction, 1:48 p.m. PT: An earlier version of this story had an incorrect spelling for a federal agency. It's US Immigration and Customs Enforcement.