Ramon de Carranza was a Spanish naval attache during the Spanish-American War who established a spy ring in Montreal. His objective was to acquire information about the American naval strategy that could have been valuable to Spanish military officials. Ultimately, the spy ring was broken by the U.S. Secret Service, and Carranza was forced to leave Canada and dismantle his operation.
(From: https://warfarehistorynetwork.com/tag/ramon-de-carranza/)
Spies, Wiretaps, and Secret Operations by 
