Currently, national security outweighs our right to privacy precisely because of the nature of the threat we in the Western world now face. While I will first elaborate on my thesis, I will subsequently explain why having to choose between national security and the right to privacy may be a false dichotomy of sorts.
Why National Security Outweighs The Right To Privacy
Undoubtedly, our biggest threats to national security are Islamic terrorist groups originating from the Middle East. Unlike adversaries of the past, these groups are elusive and kill indiscriminately. In addition to their obvious disregard for other people's lives, they show little regard for their own. Most scary of all, however, is the fact that they are extremely well-financed through the Middle East's abundance of oil (in other words, I don't see a Marshall Plan of some sort working to combat Islamic fundamentalism).
Taken together, these properties describe the worst type of threat that we in the Western world could face. Why this is so has everything to do with our high regard for privacy and the need for authorities to have probable cause before they invade it. However, with terrorists, it is not about prosecution, but preemption. Do you seriously think an Islamic terrorist who is captured after massacring more than 100 people will care about his rights as a defendant in a criminal trial? If he/she values both their life and the lives of others so little, why should we value their right to privacy?
Now, I am well aware of the main objection that could be made to my argument: there is no practical way for us to waive the rights of privacy for some and not for others; we would have to waive everyone's rights, and, by doing so, we could potentially head down a slippery slope whereby those with access to our information could wreak havoc on our lives for completely unjustifiable purposes. But, let's think here for a minute; who's to say we haven't already waived our right to privacy? Hasn't our reliance on information technology made privacy all but a completely obsolete concept?
Privacy Is An Illusion
Yes, you heard me right. Almost all of our waking hours are tracked somehow through information technology. Been to the ATM today? Your location, the amount of money you withdrew, and probably your face have all been documented by your checking account's bank. Are you logged on to WZ and not lurking as a guest? Well, we now know that you, or someone with access to your account, has been browsing these here illustrious forums (we also know exactly what threads you looked at and how long you spent in each of them).
Ultimately, the ways in which our movements and actions can be tracked is limitless. Government having access to this information involves little else than getting themselves permission to access it. So, what's wrong with trading off something that's non-existent (i.e., privacy) for something that we all take for granted (i.e., national security)? Why don't we instead work towards circumscribing the ways in which our already documented personal information can be used (e.g., letting insurance companies deny your claim for chemotherapy because you broke your arm 10 years ago) and let the authorities do what they need to do in order to ensure a peaceful future?