Re:Privacy -- It's all out there anyway, regardless of Facebook, Twitter, etc. The search engines, the artificial intelligence -- put it all together and we'd probably be amazed at how much info a determined individual could find about any of us. I remember my surprise, before the huge arise of social-networking, just playing around and doing Google searches on my kids. Surprise, surpise, my daughter and I had both made donations to one the grandkids day care, as had my brother-in-law. It just popped up there, not anything I was looking for.
Look at Amazon and Netflix. They know what you've bought, what you've considered buying, what your film interests are, and so forth. You would probably never type your bank account number online, but your bank sure has it in cyberspace, just as the govt. has your taxes.
That being said, I'm just about finished with Daniel Silva's The Rembrandt Affair, with Israeli Gabriel Allon working in tandem with intelligence agencies from the US and UK, using all the cyber stops available. I have faith they will get their man.