Don't forget the possibility that collaboration is on a "need-to-know" basis internally within Microsoft, and/or that the data is being captured by agents or coercion at the data center level.
I suspect you've been watching too many spy movies. If a Microsoft employee surreptitiously "captured" user data when asked by the NSA, he would be guilty of multiple federal felonies and subject to significant civil liability. I suppose if this were a movie, the president would secretly pardon him, or he'd get a new identity under the witness protection program or something, but, alas, this is not fiction.
Microsoft's deputy general counsel and VP John Frank has a top secret security clearance. So do at least three of its attorneys -- all those clearences were granted by FedGov precisely so the company could respond to legal requests.
Surely government institutions would never break their own rules, or lie to anyone?
To be clear, I'm not saying anything is true or not. I'm just saying we shouldn't rule anything out. It's possible that some of the tech companies are themselves partially or fully in the dark.
Government institutions frequently break their own rules, lie, and violate the law.
I suppose anything's possible, in some abstract sense, but we're talking about reality here, which excludes some more creative theories. And, alas for screenwriters, there is precisely zero evidence to support your "in the dark" theory. :)