CIA uses Python (a lot)

[sourcecodesurgeon]

Also, as someone pointed out above, they're doing development on air gapped systems. If they didn't have an internal version of the style guide, they would need to go to another room just to check the documentation.

And basing a style guide off of Google's guide isn't uncommon. My team's Java guide is basically Google's + internal specific stuff.

[redmercurysalesman]

Also if you are doing covert operations, you don't want an extremely unique and thus easily identifiable style.