[freehunter]

I'm in the same position (IT security at a large corp), with the difference that we're a Google customer. Our email and collaboration suite is Gmail/Drive/Talk/Hangouts. This means we are now recommending Chrome as the default browser on all corporate machines. Keeping Chrome locked down has been a challenge for us and not a week goes by where we don't find that someone has or is planning to attempt to bypass our restrictions by installing Chrome extensions or using web apps that integrate with Google Apps by means of giving them your Google username and password.

Google makes it extremely hard for an enterprise security team to set reasonable restrictions. Our support response from Google is usually "we don't support locking that down" or "we don't have a way to let people access feature X without also allowing feature Y". Make no mistake, Google Apps for Enterprise exists in name only.