Even Google's policies aren't—or at least weren't—foolproof. In 2010 there was a major incident involving a Google SRE named David Barksdale: https://www.telegraph.co.uk/technology/google/8003925/Google...
Of course many of the changes around that time were in response to the breach by the Chinese government, not only in response to embarrassing privacy incidents. Later improvements came about because of things Snowden published.
https://www.washingtonpost.com/world/national-security/nsa-i...
I suspect that at some stage this might come for some FANG employees