Of course. They are a web company after all. Support for all browsers.
Running a Fortune 500 company requires a large and varied set of people: managers, marketers, accountants, janitors, and even forex traders.
Janitors with access to the source code repository? I thought Google's code was reasonably clean anyway :)
I imagine most of the staff. Google makes sure all of their software works in most of the popular browsers.
Well, sure. But as I understand it, most people at Google are running Linux on their desktops. I'd expect most browser testing to be taking place in VMs or on separate boxes, and under test accounts -- which would have made the level of infiltration described in the article more difficult.
Companies like Google try to make their employees happy. If someone prefers Windows XP they are aloud to use it.