Sure, the government can use kangaroo courts and send goons to get the data, but there is nothing special about Google in this regard. They can also send G-Men to get your bank accounts, school records, health records, telephone records, safeway history, DMV records, IRS tax records, credit card accounts, library or blockbuster rentals, and tons of vital information about your behavior that Google does not have.
Nothing has changed, so if you want to stop this from happening, demand better government. Sitting around whining about Google, and then when push comes to shove, not doing your duty as a citizen, is not going to change anything.
If Google disappeared tomorrow, you'd face the same privacy issues, because simply living in a civilization creates a public paper trail, it is unavoidable. All that's different is that it's digital now, and we're networked.
Chances are you make phone calls over unencrypted mobile. The NSA could, at their perogative, intercept and transcribe every phone conversation you have. They don't even need Google. People need to fight to restore civil libertarian protections by rolling back the Patriot Act, NSLs, NDAA, and other stuff that's happened since 9/11. Trying to demonize Google will be ineffectual to the root cause.
My point about Google culture is that any attempt to put a Carnivore-style tap on a Google data center would run a very high risk of whistleblowers making it public. AT&T isn't exactly known for their Googley culture, but Mark Klein blew the whistle on the NSA/SBC/AT&T firehose tap http://en.wikipedia.org/wiki/Room_641A