Well my theory is that if Gmail was "hacked" or exposed, huge parts of the internet would be compromised.

Hundreds of millions of Gmail accounts are the central point of failure in a lot of people's lives. Each account can be used to:

- reset other website accounts

- blackmail

- identity theft

- password discovery

- socially hack connected friends, via phishing

It's a cascading failure that would completely undermine the trust of Google in the public perception.

Although this is possible I'm sure it's highly unlikely...