In a letter to The New York Times, the person police have tagged "Unabomber" said Mr. Mosser was targeted because Burson tried to change people's attitudes.
The Unabomber claimed to represent a group of anarchists and said, "We blew up Thomas Mosser last December because he was a Burston-Marsteller executive."
Misspelling the agency's name repeatedly, the letter continued: "Among other misdeeds, Burston-Marsteller helped Exxon clean up its public image after the Exxon Valdez incident. But we attacked Burston-Marsteller less for its specific misdeeds than on general principles....its business is the development of techniques for manipulating people's attitudes."
Mr. Mosser left Burson early in 1994 to join Y&R and became general manager there later in the year. Burson, while handling Exxon, never dealt with the Valdez incident.