Google and Facebook sell your detailed browsing history and social interactions to advertising companies. For a similar price, they'd likely sell this information to any government as well.
Cite your sources if you have any proof of your claim.
I didn't explicitly say they give that data to 3rd-parties, but I'll clarify that they do not give the unanonymized data to third parties (analytics from campaigns provide a fair amount of anonymized data). To the best of my knowledge, there is no method of getting discrete, individual specific data directly from these companies unless you have a subpoena.
One discussion: http://www.usatoday.com/story/money/business/2013/07/10/what...
It's easy to understand why the typical company would choose to participate if they simply need to provide a data stream to gain a new revenue stream.
It's also easy to understand why a factory will dump pollutants into a river instead of disposing them "properly". It's our job as a society to create incentives and remove options that provide this sort of "tragedy of the digital privacy commons" (not a perfect analogy).
By paying for access (at presumably a rate much greater than cost), the government makes firms who refuse to provide access less competitive in the market than firms who do.