For a year following graduation Johnson clerked for Malcolm R. Wilkey of the United States Court of Appeals for the District of Columbia.
His practice focused primarily on the emerging area of electronic commerce, including counseling on issues relating to privacy, domain names and Internet governance issues, jurisdiction, copyright, taxation, electronic contracting, encryption, defamation, ISP and OSP liability, regulation, and other intellectual property matters.
[1] Johnson helped to write the Electronic Communications Privacy Act (1986)[1] Johnson was active in the introduction of personal computers in law practice, acting as president and CEO of Counsel Connect, a system connecting corporate counsel and outside law firms, and serving the board of the Center for Computer-Assisted Legal Instruction (CALI) and as a trustee of the National Center for Automated Information Research (NCAIR).
[3] In October 1993, coincidental with the move of its main offices from Cambridge, Massachusetts to D.C., Johnson became a director of the Electronic Frontier Foundation.
[2] In February 2005, while serving as the organization's Senior Policy Fellow, Johnson replaced founder Mitch Kapor as chairman of the EFF Board.