The government works for us, right? Don't we have a right to know when "big brother" is watching? Our internet communications should be as secure as federal mail. No one should have a right to that information without due cause and a search warrant. If someone is asking about my data, I want to know about it. I appreciate the government's efforts to defend the nation, but not at the cost of invading the privacy of innocent Americans.
If the authorities present Google with a court order for user data, then like any other request, it should be granted. But to simply release information on spontaneous requests seems unconstitutional, and under no circumstances, should be allowed. This would prove to be a very dangerous practice, and I can't imagine that it would be relatively beneficial.
As frustrating as the government can be sometimes, we hire them to protect us, and sometimes secrecy is needed for the best results. While it can feel upsetting to be in the dark about something related to national security, the government can't always tell everyone everything, or they could end up creating more harm than good.
99% of the time, the release of this information would do no one any good at all. Instead, we would citizens constantly questioning each other. Radicals may even start to personally harrass individuals that the government has looked at. The government has to have the ability to look at data on users to save lives. Let's leave it to them.