When they started to unionize, Amazon tried to get rid of them.
That's the argument at the heart of a strike by more than 80 delivery drivers in California, who have taken legal action against the online retail giant in a case that could have major implications for the way it operates in the United States.
For the past month, employees have manned a picket line outside an Amazon warehouse in Palmdale, north of Los Angeles, slowing down vans that carry the company's packages.
Their strike is "not for our building alone -- we want to go nationwide," said Michael Leib, a 31-year-old driver.
Leib works for Battle-Tested Strategies (BTS), one of more than 3,000 small businesses in the US that exclusively deliver packages for Amazon.
Fed up with faulty air-conditioning and windows that didn't open in their Amazon-branded vans in California's heat, and being forced to work at breakneck speed, BTS workers unionized in April.
They demanded better working conditions, and a pay rise.
But barely a week before they formally unionized, Amazon announced the cancellation of BTS's contract. Since the end of June, the retail giant has ceased all activity with the subcontractor.
"We want to have safer working conditions, we want to have a higher pay wage," said Leib.
"And the fact that you don't want to do that for us when you're a multibillion dollar company? That's not fair."
- 'Fear tactics' -
Critics allege that Amazon -- which has steadfastly opposed organized labor in its massive workforce -- has used similar tactics before.
Back in 2017 in Michigan, another subcontractor whose delivery drivers unionized had its contract canceled.
When Amazon employees at a New York warehouse last year voted to unionize, the company took legal action to block the move.
"Amazon is employing textbook fear tactics and union-busting throughout," said Christian Castro, a spokesman for the Teamsters Union -- the powerful organization representing truck drivers across the US which BTS workers joined.
"You try to stand up for yourself as a worker, as a person, and they're going to squish you, they're going to take you out," said Castro.
To resist, the union has filed an unfair labor practice charge against Amazon with the National Labor Relations Board, and BTS drivers went on strike.
If the federal agency steps in and forces Amazon to negotiate with the union, it could fundamentally challenge the company's business model.
Amazon has said that BTS workers, like those among its 3,000-plus other subcontractors, "do not work for Amazon," and has accused them of spreading a "false" narrative.
But BTS workers reject Amazon's claim, noting that they operate everywhere with the retail giant's logo and under conditions it sets.
"We work for Amazon because we're wearing their shirts, we deliver their boxes, we drive their vans, their shipping labels are all over the boxes," said Leib.
When he's asked for a raise, Leib said, "the owner of the company said, 'Well, let me ask Amazon, to see if I can get more money from them so that I can pay you.'"
Amazon did not respond to AFP's request for comment.
- 'Exhaustion' -
Leib said he has endured three years of working in "very harsh conditions," including temperatures of up to 129 degrees F (54C) inside his van during California's sweltering summers.
Drivers are expected to deliver more than 400 packages a day, with supervisors remotely keeping tabs on their progress.
"You've got dispatchers breathing down your neck, saying, 'Hey, what's going on? Why are you slowing down?'" he said.
"I felt heat exhaustion. I felt nauseous... and nearly collapsed" last year, Leib said.
Despite this, Amazon says it terminated BTS's contract because the subcontractor was consistently under-performing and missing its targets.
BTS boss Johnathon Ervin, a military veteran, strongly disputed this, claiming his employees set records and delivered up to 20,000 packages per day.
"Does that sound like low performance to you?" he asked.
Ervin's company was cited as an example in an Amazon newsletter in 2020.
And last November, an Amazon performance review said BTS's risk of non-renewal was "low."
According to Ervin, Amazon had been aware for over a year that the Palmdale delivery drivers wanted to unionize.
Last August, Amazon approached BTS with an offer of management training.
"It ended up being an anti-union training," Ervin said.
"They said that if workers unionized, they would cancel our contract and they gave us strategies on how to prevent unionization."