The chips in question are not counterfeit.
They're a completely different rs232 device which uses the same command api as fdti''s one. The big sin is using ftdi's USB ID (naughty but common and the basis is that they work alike. They should use one the generic serial device ID if they don't acquire their own one)
There was an analysis of the silicon last time around. The "fake" devices are actually better implemented than FTDI ones and they can be bricked specifially because they adhere to the published command set better than ftdi''s own silicon does.
I suspect that deliberately bricking chips in the UK will come down to the computer misuse act. This could get interesting. ...
The fact that FTDI is setting these to a zero or random I'd is extremely telling. Apart from the dubious legality of trashing end-user equipment they _could_ have reset it to 'generic rs232 device'.