Back in October 2014, the company shipped a device driver that checked the authenticity of USB chips claiming to be FTDI. If it detected a non-original chip, the driver would stop the host operating system seeing the device by setting its USB product ID to 0.
That release led to criticism that the company was penalising people who didn't know they had an infringing product.
I kinda like that as a solution -- it's certainly better than interfering with the data stream -- but wouldn't it have been better if FTDI had registered a second USB vendor ID as "Fake FTDI", and set the USB device ID of any non-original chip to that code?
The device would continue to work, but any system tools like Device Manager on Windows or lsusb on Linux would display the fact that the hardware was non-original, and questions would be asked.
... then again, I wonder why the driver even installs if there is no genuine hardware for it to drive. FTDI could have saved themselves a world of trouble by simply not recognizing fake hardware.