He is the CEO and co-founder, with computer scientist Celine Bursztein, of Recent Media Inc., a startup in Silicon Valley that has built a recommendation engine and iOS and Android news app. Recent, which uses artificial intelligence and machine learning for its recommendation engine, was released to early users in June 2015.
He previously worked for Wired, CNET, CBS Interactive, and Time Inc.. His articles about technology have been published in Playboy, the Wall Street Journal, Communications of the ACM (co-authored with computer scientist Peter G. Neumann), and the Harvard Journal of Law & Public Policy.
Previously as a journalist he specialized in computer security and privacy. He is notable, among other things, for his early involvement with the media interpretation of U.S. presidential candidate Al Gore's statement that he "took the initiative in creating the Internet." McCullagh once joked that "If it's true that Al Gore created the Internet, then I created the 'Al Gore created the Internet' story."
In addition to technology, McCullagh has written approvingly of free markets and individual liberty. He began writing weekly columns for CBS News entitled Other People's Money upon CBS Corporation's acquisition of CNET Networks. In August 2009, McCullagh renamed his column to Taking Liberties, which focuses on "individual rights and liberties, including both civil and economic liberties."
- "AngelList web site". Retrieved June 30, 2015.
- "Recent Media Inc.". Retrieved June 30, 2015.
- "Recent beta has been published". June 26, 2015. Retrieved June 30, 2015.
- McCullagh, Declan (November 20, 2000). "ICANN Use More Web Suffixes". The Wall Street Journal. (wsj.com). Retrieved June 30, 2015.
- McCullagh, Declan (June 1999). "Inside risks: risks of Y2K". Association for Computing Machinery. (acm.org). Retrieved June 30, 2015.
- McCullagh, Declan (Fall 2001). "Technology as Security". (harvard.edu). Retrieved June 30, 2015. (subscription required (. ))
- McCullagh, Declan (October 17, 2000). "The Mother of Gore's Invention". Wired News. (wired.com). Archived from the original on May 26, 2008. Retrieved August 1, 2007.
- McCullagh, Declan (September 12, 1997). "In Defense of Libertarianism". Wired News. (wired.com). Archived from the original on October 21, 2008. Retrieved September 16, 2008.
- McCullagh, Declan (August 19, 2009). "Welcome To "Taking Liberties"". CBS News. (cbsnews.com). Retrieved August 28, 2009.