This case involved a constitutional challenge to the Telecommunications Privacy Protection Act, which broadly permitted investigative agencies to conduct real-time location tracking using communication verification data.

The petition aimed to highlight the constitutional concerns surrounding the unrestricted collection of sensitive location information.  
Designated as a pro bono case by the firm, Attorneys Yoo Jung Lee and Ji-Heon Oh led the constitutional litigation. The petition was filed in February 2012, and after a public hearing held at the Constitutional Court in July 2017, the Court rendered its decision on June 28, 2018—six years after the initial filing.  

The Constitutional Court ultimately ruled that the relevant provisions of the Act were incompatible with the Constitution, citing violations of the right to informational self-determination and the freedom of communication. This landmark decision prompted legislative reform and reinforced constitutional safeguards against excessive surveillance.