Hundreds of Amazon workers blew whistles and banged drums on Tuesday as they protested against working conditions in Germany where the megagroup's founder Jeff Bezos was receiving a prize.
Chanting and holding banners reading "Make Bezos pay", about 450 workers gathered in front of the German publishing group Axel Springer in Berlin where the Amazon boss was to receive an award at a glitzy ceremony attended by politicians and celebrities.
The prize, given by the publisher of German's mass-selling daily Bild, rewards innovation in business, but the choice of Bezos was met with anger among unions and some politicians, according to the Daily Mail.
"We have a worldwide problem, a boss who wants to impose American working conditions on the world," said Frank Bsirske, head of the Verdi union representing Amazon workers.
"It's like going back to the 19th century."
Andreas Nahles, head of the Social Democrats that are in coalition with Chancellor Angela Merkel, said Bezos "didn't deserve any prize", pointing to working conditions at Amazon sites in Germany.
Verdi has organised frequent strikes at Amazon in Germany since May 2013 to press demands for the retailer to raise pay for warehouse workers in accordance with collective bargaining agreements in Germany's mail order and retail industry.
Organisers of Tuesday's rally said Amazon workers came from as far afield as Poland and Italy to voice their displeasure.
The French CFDT union said the gathering "denounced illegal practices and disastrous working conditions" in the company.
It said there had been "several undeclared workplace accidents" and accused Amazon of monitoring the computer records of employees.
Bezos - the richest man in the world, according to Forbes magazine - was quoted by the German DPA news agency as saying he was "very proud of our working conditions" in response to the gathering.
In March, Spanish Amazon staff held their first work stoppage to protest new working guidelines.
Amazon boasts more than 560,000 employees, and reported a profit last year of slightly more than $3 billion ($4.2b).
The company has previously said that its salaries are at the higher end of the logistics sector range and employees enjoy attractive benefits.
Amazon has repeatedly rejected Verdi's demands, saying it believes warehouse staff should be paid in line with competitors in the logistics sector, not as retail staff.
An Amazon spokesman said on Tuesday: "Amazon provides a safe and positive workplace for thousands of people across Germany with competitive pay and benefits from day one."