I recall a children's book in the "boy detective" genre, in which the villain was stealing the used typewriter ribbons from the dumpster of some businesses and

I recall a children's book in the "boy detective" genre, in which the villain was stealing the used typewriter ribbons from the dumpster of some businesses and reading the information on them. The "it must be some computer whiz breaking our database!" plot was a major red herring, but the characters believed it, because computer security was under closer scrutiny. This seems to be the same sort of problem: digital data is insecure and people will try to steal it, but paper isn't.