It is true that exactly the same commands are sent to the genuine and counterfeit components, but on genuine FTDI parts it does literally nothing. Here is a com

It is true that exactly the same commands are sent to the genuine and counterfeit components, but on genuine FTDI parts it does literally nothing. Here is a commented decompilation: https://twitter.com/marcan42/status/525202516816842752 https://twitter.com/marcan42/status/525202516816842752 It is very hard for me to picture any purpose this code could serve other than deliberately bricking counterfeit devices. FTDI has offered no explanation. There were some tweets (now deleted) from FTDI which didn't outright admit to it, but rhetorically asked for a better way to fight counterfeits. USB is sort of a baroque and unpleasant protocol, and much more of a pain in the butt than RS232. But it is probably less of a pain than depending on a supplier who will deliberately damage end users' property in the field and insist they did nothing wrong, before insisting they did nothing at all in a denial that insults the reader's intelligence.