National security only trumps the right to privacy when the party imposing security measures (e.g. the U.S. Government) is truly functioning in the interest of the people it is imposing such measures upon, to protect them from those who would do them harm (e.g. Terrorists). That is the circumstance we are faced with today. Some of the current clamor on domestic surveillance ignores the greater risks and evils we face.
For example, with enactment of the Health Insurance Portability and Accountability Act in 1996 (better known as HIPAA), the government reserved the right to review your medical records without court approval, if such an action is deemed potentially useful to a federal investigation. I wasn't particularly concerned about that in 1996, nor am I now. How many abuses of that legislation have been documented in the last five years? Ten years? In many cases, I think our right to privacy -- concerning one's health records and profile were dramatically strengthened by HIPAA, as opposed to invading our privacy on health matters.
Now consider the loudest domestic surveillance concerns we hear today and ask yourself if you think the CIA or NSA cares about phone calls you have made, or books you have checked out? I prefer to believe that only those people trying to harm freedom-loving good citizens like us, should be the ones worrying. At least that's the way I feel today, but governments can and do change into despotic forces so we should always look over their shoulder(s) too. This is not a static issue.