Amazon CEO Jeff Bezos has just become the richest man in recorded history—surpassing $150 billion in net worth—thanks to his business model of subjecting employees to low wages, brutal working conditions, and scant benefits, and on Tuesday Amazon workers throughout Europe are marking "Prime Day" by walking off the job in massive numbers to call attention to their plight.

"Jeff Bezos' newly renovated home in Washington DC will have 25 bathrooms. Meanwhile, Amazon workers skip bathroom breaks in order to meet their grueling work targets."
—Sen. Bernie Sanders

In addition to walkouts by an estimated 80 percent of the workers at Amazon's largest distribution center in Spain—nearly 1,800 workers—employees of the retailer are also reportedly launching strikes in Germany, France, Italy, Poland, and the United Kingdom to demand higher wages and denounce Amazon's union-busting efforts.

"The message is clear—while the online giant gets rich, it is saving money on the health of its workers," Stefanie Nutzenberger, spokesperson for the German services union Verdi, said in a statement.

Strikes against Amazon's notoriously appalling working conditions—which include forcing warehouse employees to skip bathroom breaks and urinate in bottles to meet the company's unrealistic performance expectations—come as Bezos is coming under growing pressure to address his treatment of employees.

As Sen. Bernie Sanders (I-Vt.) pointed out in his "CEOs vs. Workers" town hall Monday night—which Bezos declined to attend—the Amazon chief earns around $275 million each day while refusing to pay his workers enough to get by without food stamps.

Seth King, a former Amazon employee who participated in the town hall, described Amazon's business model as "a revolving door of bodies" and said workers are "not allowed to sit down" or "talk to other people" on the job.

In solidarity with striking workers throughout Europe, many in the U.S. and throughout the world are calling for boycotts of "Prime Day," which lasts 36 hours.