The use of hacking (I hate the *ethical hacking* name) techniques can be used for more than penetration testing and red team assessments. In one occasion, my team helped a law enforcement agency in the collection of information that lead to the capture of a criminal.
The owner of a company contacted the authorities about a former employee that took with him very sensitive and valuable proprietary information. They have some proof of it and were hoping the authorities could help locating and acquiring the proof he needed to take this person to court.
After a few months of not going anywhere the company contacted us to see whether we could help the law enforcement officials locate and track the former employee (I'll refer to him as Bob). We were given all the information, including some really nice open source intelligence collected by the good guys. Two pieces of information gave us a good lead: Bob's personal email and his social media information.