From Orin Kerr (The Volokh Conspiracy):
For those with criminal law experience, this was basically a large-scale pen regsister/trap-and-trace or wiretap. . . .From anarcho-libertarian David Friedman (Ideas):
[T]he details of the program from [James] Risen's book [State of War: State of War : The Secret History of the C.I.A. and the Bush Administration] arguably explains the national security interest in keeping the domestic surveillance program a secret. It's not that terrorists may suddenly realize that they may be monitored; that argument never made much sense, as every member of Al-Qaeda must know that they may be monitored. Rather, I suspect the security issue is twofold. In the short term, terrorist groups now know that they can stand a significantly better chance of hiding their communications from the NSA by chosing communications systems that don't happen to route through the U.S. And in the long term, some countries may react to the disclosures of the program by redesigning their telecommunications networks so less traffic goes through the United States. The more people abroad know that the NSA can easily watch their communications routed through the U.S., the less people will be willing to route their communications through the U.S. Cf. Bruce Hayden's comment. No doubt it was a long-term priority of the NSA to ensure that lots of international communications traffic was routed through the U.S., where the NSA could have much better access to it. Indeed, Risen's book more or less says this. The disclosure of the program presumably helps frustrate that objective.
A computer wiretap is not really an invasion of privacy–nobody is listening. Why should it require a search warrant? If I were an attorney for the FBI, facing a friendly judiciary, I would argue that a computerized tap is at most equivalent to a pen register, which keeps track of who calls whom and does not currently require a warrant. The tap only rises to the level of a search when a human being listens to the recorded conversation. Before doing so, the human being will, of course, go to a judge, offer the judge the computer's report on key words and phrases detected, and use that evidence to obtain a warrant.And from Tom Smith (The Right Coast):
Jack Balkin has a very good point here.The use of surveillance to create databases from which law-enforcement officials can, with proper judicial oversight, solve crimes and detect actual criminal conspiracies is one thing; the use of those same databases to anticipate or imagine conspiracies is quite another thing, against which we should be on guard. But the second possiblity should not serve as an excuse to prevent the use of surveillance to detect actual or incipient conspiracies to commit acts of war against the United States.
To add to it a little bit, technology on the data mining front is moving very fast. In fact, the term data mining is too narrow and somewhat dated. For just a taste of one cutting edge approach, check this out. This company takes a semantic network approach to unstructured databases. There are other approaches as well.
What I am getting at is, if the government puts together a huge database -- and Jack is absolutely correct; it is within their capabilities, well within -- then with tech from the private sector, not to mention what NSA geniuses come up with, then what they can figure out about individuals, firms, and so on, really does not have any clear limit. It is not at all far fetched to say if the government wanted to, it could know more about people than they know about themselves, a lot more.
There are many questions here. The first is whether the storage of this information violates constitutional protections. I think sentience may make some difference here. If every email you have sent in the last five years is stored in some place the government has access to, but they do not actually access it, then I'm not sure your privacy has been affected at all.
But here is something that worries me, though maybe it shouldn't. Search algorithms are already astonishingly powerful. They are advancing rapidly. It may be possible soon to pull out from such things as patterns of emails, phone calls, puchases and the like, people likely to be involved in drug trafficing, money laundering, whatever. If an impartial algorithm can troll through a database and produce a list of people who really are, to some high degree of probability, connected with herion trafficking say, should that be enough to support a warrant to start the really intrusive, traditional sort of surveillance?
I have already made clear that I think the President should be able to do exactly this if it is necessary to fight a war. But law enforcement agencies doing it does strike me as pretty creepy. It could be an extremely powerful law enforcement tool, though.
P.S. This is worth reading.