There are accounts of interdiction and post-manufacturing compromises, such as those revealed in the Snowden leaks (2013) and most recently by reporting about the Israeli security services' sabotage of Hezbollah pagers and 2-way radios. These projects didn't expose primary manufacturers to the reputational and legal risk of association.
Until there's evidence of backdoors implanted by these companies, it's better to adopt a "trust but verify" approach and use standard layered security practices to detect intrusion. Conventional network intrusion and insider threat campaigns carry less risk of failure and are simpler and cheaper to execute.
Intel's ME comes really close to that, but I don't think Intel's ME has drivers for every possible NIC and bus a NIC can appear on in its little Minix. So, just put a Broadcom NIC in a PCIe slot and leave the Intel onboard NIC empty, or LAN facing only.
Xiaomi may get Chinese 4G/5G baseband chip manufacturers to put in backdoors in Chinese phones, but they're not needed - the Chinese government pretty much already has total control of its Internet. For other countries, how are they going to make Qualcomm provide something undocumented CPU instructions can access.
Not knowing a thing makes someone uninformed, not retarded.
The existence of undocumented hardware behavior isn't proof of anything.
Now, if the EU would start make to make chips that have no subsystem to screw me over, that would be something.
Why would they not do the same? They are very pro-surveillance for a start.
They are backdoors, with not even very good plausible deniability.
It's so on the nose it's comical.
The answer to that question in the US is within epsilon of “no” thanks to the cloud act.
Europe and China have passed similar laws. However, China has a reputation for passing laws then selectively enforcing them. Maybe if you get on the right side of the right party member, the answer might still be “Yes” there.
Anyway, the next question to ask is: Who would I rather backdoor my device?
I doubt the Chinese government cares much about me, and unless I vacation there it’s an international incident if they, say, hack my car and murder me by aiming it at a tree at 95mph, like the CIA apparently does now:
https://www.motor1.com/news/138679/wikileaks-claim-cia-hack-...
Of course, the US government banned cars from China. Presumably this is because they do not have the mandated remote murder network port open, or, if they do, the US doesn’t have the necessary permissions to access it.
Would Xiaomi or the CCP accept the reputational and legal risk of getting caught with a backdoor? Recall the CCP considered the arrest of the Huawei executive in Canada as an offense against itself.
For instance election tampering in the US is a well-documented thing: However it almost always favors republicans in districts with electronic voting machines that do not generate paper trails.
As for the person you are replying to, their claims have been documented by most media outlets, places like wikileaks, and their claims are backed by US legal requirements to backdoor stuff (like the US Cloud act).