Harold is Public Knowledge's Senior Vice President. Before becoming Senior Vice President at Public Knowledge, Harold worked as Senior Vice President of Media Access Project, advocating for the public interest in media, telecommunications, and technology policy for almost 10 years. Prior to joining MAP, Harold was an associate at Covington & Burling, worked on Freedom of Information Act, Privacy Act, and accountability issues at the Department of Energy, and clerked for the D.C. Court of Appeals. He received his B.A. from Princeton University, and his J.D. from Boston University Law School. Harold also writes Tales of the Sausage Factory, a progressive blog on media and telecom policy. In 2007, Illinois Senator Dick Durbin praised him and his blog for "[doing] a lot of great work helping people understand how FCC decisions affect people and communities on the ground."

Feld is a frequent public speaker on issues pertaining to telecommunications, technology, entertainment and law.