You accept failure as a possible outcome of some of the experiments. If you don't get failures, you're not pushing hard enough on the objectives.
I knew from the beginning that privacy was going to be a huge issue, especially with regard to applying Total Information Awareness in counterterrorism. Because if the technology development was successful, a logical place to apply it was inside the United States.
I really believe that we don't have to make a trade-off between security and privacy. I think technology gives us the ability to have both.