I remember an article from years ago (~10-15) about how Cisco Systems realized that one of their contract assembly houses has ripped off one of their products and was selling it at 25% of their price. Same product, same production line, different Logo on the product in a plain white box. There are countless stories like this.
Right down to the serial numbers.
Cisco detected the problem when they got multiple service/maintenance request for the same serial number server in widely separated locations.
They tracked down the company making the clones, and that company's response to Cisco's futile attempt at getting a Chinese court to issue a cease and desist order was to blandly offer to build the servers for Cisco!