We have to be careful defining about exactly what "it" is. I'm operating under the assumption that the NSA is collecting call data records from phone companies, and getting downloads of peoples' Google/Facebook/etc accounts pursuant to court orders that don't meet the requirements of Article III warrants. I reserve judgment on any activity that isn't covered by the above.

If that is what is actually happening, I think it is at least legal Constitutionally. I think the third party doctrine is alive and well, and I agree with Orin Kerr that it makes 4th amendment analysis technologically neutral (http://www.abajournal.com/magazine/article/the_data_question...). Basically, if I print out my e-mails and leave them in my friend's garage, the police do not need a warrant to get them, they can use a subpoena or lesser court order to get him to produce any documents I gave him. So why should those e-mails be protected if, instead of printing them out and leaving them in my friend's garage, I instead keep them in digital form on my friend's servers and my "friend" is named Google?

I think it's also consistent with how the framers understood the 4th amendment. It creates a zone of privacy around you that protects you from invasive search and seizure. It protects your person, it protects your house, it protects your property. It does not attach to the information itself and follow it around wherever it goes.

And I think with call detail records the 4th amendment isn't even implicated, because it's not even your data in the first place. It's data generated by Verizon's or AT&T's computers in response to signals on their networks. It's like a 7/11's security cameras. It's not a violation of your 4th amendment rights if your trip to the local 7/11 was captured on a security tape the store handed over to the police.

I think the NSA's programs are actually more likely to run into problems with the Electronic Communications Privacy Act or the Stored Communications Act.

Vis-a-vis FISA court warrants, I absolutely agree that they do not pass muster as Constitutional warrants. That is to say, if a search was deemed to require a Constitutional warrant for 4th amendment purposes, the police could not offer a vague FISA warrant to meet the requirement. But at the same time, I don't think collecting say call detail records from Verizon is something that requires a Constitutional warrant in the first place.

There is a very deep distinction in the law that I think a lot of people want to ignore. Your information in your possession is protected much more strongly than information pertaining to you in the possession of other people. The police need an article III warrant to bust into your house and take your accounting records. The police need merely a subpoena to get copies of your accounting records from your accountant. Similarly, a court cannot compel you to testify against yourself (5th amendment). But it can definitely compel your friend to testify against you. This is an asymmetry based on qualitative distinctions that transcend technology (i.e. your information versus information pertaining to you.) It's not like new technology has changed this distinction, all it has done is make it much easier and more convenient to give your personal information to third parties.