If it was not unsafe they would not sell a new Windows version or what ?
Not to talk about NSA stuff ( Microsoft is American company ).
So for me its clear, cannot be trusted with your stuff.
China and every other major country is also trying to read your information and the information of major corporations.
The difference between China breaking into Google and the NSA breaking into Petrobras, is that China steals the trade secrets and gives them to their businesses, and the NSA doesn't re-distribute trade secrets. If you're worried about the NSA having what Google already collects on you, then you should be worried about the amount Google collects and focus on cutting of the source of the NSA's information.
NSA doesn't steal your source code and give it to your competitors. China and Russia does.
Really, Israel is the only one who's had a realistic response to the whole NSA spying on them thing.
They basically said, "Oh, the NSA was spying on us? That's what we expected. We expect every first world nation is, just as they correctly suspect we are." (I'm totally paraphrasing here)
Any other reaction is delusional, in my opinion. "Gasp! The spy agency has been spying on people?! Crucify them for doing their job!"
The only real shock here is that they did their job fifty times better than anyone expected (kudos for them, that shows their skill) - and that they were skillful enough to hide it (kudos for them, that shows their skill).
Israel, and dozens of other first world nations, share-in and process loads of NSA-collected information, and share with the NSA loads of information their own spy agencies collected.
The other-country outrage of places like Brazil is not that the NSA were spying (because Brazil spies on us also), but that the NSA succeeded, and worst still, without their knowing. It harmed their national pride, and made them feel weak and vulnerable, because they now knew they were exposed, didn't know what was stolen, and didn't know how badly they were exposed or where, but knew it was bad.
When it was found out the USA had spied on Israel Prime Minister, it was also revealed by Snowden that Israel had spied on the French President just last year (that is to say, the French discovered it last year, but I don't know how long Israel was spying before being discovered). Many countries, NSA shares some of its spying information with. They aren't ignorant that other countries (other allied countries) are spying. While the USA is sharing loads of spying information with countries like Australia, do you think they aren't sharing similar or different information with France and Germany?
When visiting other (friendly, allied) countries, our diplomats are taught to assume they are being spied on. Because they are. They have to go inside their eavesdrop-protection tents that they bring with them, if they want to have a secure conversation. The host nations of our allies like Britain, bug the hotel rooms that they assign to our visiting diplomats.
Heck, someone I know real well went to Cuba on a church mission-trip a few years back, and Cuba wiretapped the hotel rooms just because they were American.
The only thing we've gotten out of the Snowden revelations is that, hey, at least one department of our government is actually competent and does their job efficiently and effectively. The media/public/political solution? Shut down one of the few parts of our government that actually works.
</rant> *deep breath* *goes back to programming*