Are there adequate constitutional safeguards to maintain people’s privacy as the means for data collection, physical evidence, eavesdropping capabilities expand?
In principle, yes. However, this will depend to a great degree on how the courts rule with regard to the application of some of this technology.
For example, there is a case that the Supreme Court is currently deciding that has to do with the use of GPS devices to track people's movements. Will the Court hold that police agencies can, without a warrant, put a GPS device on a person's car and thereby know every place that person goes and how long they stay there?
There is also the issue of drone technology. The basic rule right now is that anything you have or do in your yard that can be seen from the air is fair game--you have no expectation of privacy. But will that rule be adequate to protect our privacy if drones can stay up for long periods of time and observe us constantly?
These are no explicit guarantees against these sorts of expanding capabilities. We will simply have to see whether courts choose to interpret current safeguards (like the 4th Amendment) in ways that adequately protect our rights.