According to Quartz, the source code that Google used was contributed by the secretive National Security Agency. This means that each phone could come with its own special link to US espionage, and might explain why China is still not that happy with Google.
So while the US is busy banning Chinese phone companies because they might have links with Chinese intelligence, it appears that Google really does have NSA code under its bonnet.
An NSA researcher told Bloomberg Businessweek that Security Enhancements for Android is one of several projects the US spy agency contributes to open-source operating platforms.
The idea of the code was to raise the bar in the security of commodity mobile devices. It is supposed to be providing anti-hacking protection. After the Snowden disclosures you can understand why there are worries it may contain something toxic.
Snowden revealed that the US agency hacked millions of Chinese SMS messages and is working closely with American technology firms. It might be the reason that so many local Chinese firms like Baidu, Huawei, and Alibaba are rushing to develop their own operating systems or at least an independent variant of Android. It might take a few years, but it does suggest that in the long term, Android is toast in the country.
There is also another implication. If the NSA provided code, does that mean that it could be sniffing phones as well, regardless of 'friendly' or 'hostile' nation?
Snowden revealed how the NSA had no problem bugging EU communications as part of its spy operations.
Combining Android's popularity with generic smartphone features like two cameras, a microphone, and communication apps, Android could be a particularly useful tool for US spooks to snuffle data, everywhere.