Surely Google and Facebook do this too. Why are we surprised that the government does it?
There have been what... 3, 4 deaths from terrorism this year in the USA? And 6,000+ deaths by way of guns/criminal activity? Doesn't really seem to be worth their trouble to be snooping through who I talk to and who I hang out with.
Also, by your logic, it's not your information anymore - you have given it to Google and Facebook, which makes it their information to give to the government.
I choose not to do so, I don't use facebook or gmail, but if I did I would only expect them to be using and abusing it, not some secret government program.