Can/should the NSA telephone meta data be used for good purposes?

Most everyone would agree there is potential for the data to be used in bad ways. But is it possible to use the data for good?

Since the data already exists, why not use it to track down violators of the Do Not Call list? Can it be used to stop and fine telemarketers? Can individuals use it as evidence in court cases as proof that they were being stalked, for example? Can police use it to find suspects in felony cases?
How about using the data to predict weak links in infrastructure and identifying regions that need service upgrades?
Beyond the intended purpose (whatever that might be) I can see so many ways the data could be useful. Do you?