From 1999 to 2007, he wrote about technology, libraries, and archives for The Chronicle. His 2001 article, "The Deserted Library," which questioned the value of library places in an online world, became the focus of academic conferences and journals. "Few articles caused as much of a stir among academic librarians," Library Journal said in 2003.
In 2006, he broke the news that the FBI had plans to rifle through and censor the notes and papers of the influential investigative journalist Jack Anderson, which led to Senate hearings and outcry from journalists. Carlson won first prize in beat reporting from the Education Writers Association that year.
He is a frequent contributor to Grist, a popular site for environmental news, and has also written for national magazines such as the Utne Reader and Dwell. He lives in Baltimore.