Foxconn is PS4 manufacturer in China. Recently, it was reported that the factory’s employees are selling PS4 parts online using services such as eBay.
Thumbsticks for the PS4 controller are available to buy from eBay and, tellingly, are shipped from Shenzhen in China, which is where Foxconn's largest factory is based.
Foxconn Staff are Selling PS4 Parts Online?