Generally when people think about civil litigation – lawsuits – they think about suing some known or at least identifiable individual or entity. The paradigmatic example would be a motor vehicle accident in which John Smith runs a red light, hitting your vehicle, causing you property damage and injuring you. Perhaps, in that scenario, your attorney might file suit against John Smith and in preparing the case for trial learn that John Smith shares blame with the City for maintaining a dangerous intersection where the timing of the traffic lights is off, causing motor vehicle accidents. The attorney would in this scenario then add the City in as a defendant in the suit. However, a more interesting case arises in which the wrongdoer is not immediately apparent and traditional means of investigation do not bear fruit. 
 
Consider a situation in which a corporation learns that its credit card points have been transferred without its consent. These points actually have a significant cash equivalent value, but there is no mechanism for determining how the points were transferred, by whom, and to what destination account. The credit card company is not cooperating with the company in providing that information. Law enforcement is not interested in investigating what strikes them as bizarre, and a civil rather than criminal matter.  The corporation could file a complaint and summons for the tort (civil wrong) of conversion against John or Jane Doe. This opens up the possibility for the corporation to then use the tools in the civil litigator’s toolbox to find out the details surrounding the wrongful theft of those points. Here, the corporation can find out who is responsible for this theft by issuing a subpoena duces tecum on the credit card company.
 
Janssen Malloy LLP has occasionally used this technique to help clients obtain needed information that would have remained unreachable but for the opportunities created by filing a civil suit against John or Jane Doe.