One of the complainants, Taree Truong (who delivered packages full-time for Prime Now from September 10th to October 5th), told The OC Register:

When I was hired, I was told that I would be paid $11 an hour plus tips and $2.50 per delivery. In September, I had to sign a new contract that eliminated the delivery fee. But I never see an accounting of what tips I receive, because everything is paid through an app. I have no way of knowing whether or not I have been paid what I am due.

Truong and the other plaintiffs were contracted through Scoobeez, one of the third-party courier services Amazon uses. They've since left the LA-based provider and have actually sued it alongside the e-commerce website. The online marketplace is just one of the many tech corporations dealing with on-demand-worker-related lawsuit. One of those cases was filed against Uber by three drivers in California demanding compensation and benefits that employees enjoy. A judge ruled in September that the Uber case was entitled to fall under the class-action status, something the delivery drivers' lawyer hopes to replicate.