Wiretapping and Electronic Surveillance in America, 1862-1920 - Kerry Segrave - Bog

Gives a faithful overview of the history of tapping: it all started in 1910, when the dictograph arrived and made it easier still for people to engage in spying telegraphic communications. It was the first ready-to-use bug that anyone could employ - that is, buy it off the shelf and use it with no prior training required. Politicians dictographed other politicians; corporations dictographed labor unions; stockbrokers bugged other stockbrokers; and the police dictographed everybody.