Amazon has been fined €32m (£27m) in France for "excessive" surveillance of its workers, including measures the data watchdog found to be illegal.
The CNIL said Amazon France Logistique, which manages warehouses, recorded data captured by workers’ handheld scanners.
It found Amazon tracked activity so precisely, it led to workers having to potentially justify each break.
This, the CNIL said, was illegal while it also questioned why Amazon needed to keep workers’ data for 31 days.
France’s data protection agency investigated Amazon warehouses following complaints by employees as well as media coverage of conditions.
It outlined a number of areas where it found Amazon had breached General Data Protection Regulation (GDPR).
One alert triggered if an item was scanned too quickly or less than 1.25 seconds after scanning a previous item.
Another signalled breaks of 10 minutes or more, while a third tracked breaks between one and 10 minutes.
The CNIL said Amazon already had access to lots of data to achieve quality and safety in its warehouses, and called the system “excessively intrusive”. It also noted that tracking employees so closely could lead to them having to justify even a brief interruption of scanning.
Amazon also used data collected by the scanner to plan work in its warehouses, evaluate employees on a weekly basis and train them. The watchdog ruled Amazon did not need access to the smallest details of data collected by the scanners to do so.
The online shopping giant was fined for not properly informing workers and external visitors about surveillance, with the watchdog also found to have had insufficient security on its video surveillance.