The cynic in me thinks that Google is deliberately fighting a losing battle, so that later on they can say, "Hey, it's not our fault -- we want to tell you what is happening, they won't let us!"
If they wanted to fight, they'd just publish the info instead of asking some court before doing anything.
Then again, it's doubtful whether anyone would believe them at this point if they published anything and claimed the information was complete.
The companies involved are taking these actions because the leak may have undermined consumer trust (eg. small drops in activity) in them. Perhaps even wrongly, if PRISM isn't as widespread as the initial leak suggested.
Secondly, if what you say is true, then we should stop complaining about what Google passes it to the government - what business is it of ours what they do with their data?
Thirdly, I doubt that anyone seriously believes that the 'fee' for using GMail is that their messages become Google's property.
You know the old saying, "If you're not paying for a service, you're the product." Why expect anything else? Google is a for-profit company and it's an expensive thing to run. They deserve something for the services provided, don't they?
But, if things are as you say, Google can do whatever it likes with the data according to the ToS. If people don't like data about them being given to the Government, or used for any other undisclosed purpose, they shouldn't have used Google.