Re: Is there any proof?
It has been commonly reported that US technology companies were doing precisely what the US government is accusing China of.
It stands to reason, that the Chinese would have the desire, motivation and capability to do so. So in principle we have to assume they are doing so, much as they publicly admit they do on their own citizens (although presumably more targeted abroad).
I seem to recall that the UK government had a specific software team that had the explicit role of studying Huawei software and electronics for suitability/backdoors.
Biting the hand that feeds IT
