World 1st Hacker exploit communication technology for lulz in 1903. Nevil Maskelyne was first in a long line of hackers who have exposed and exploited security flaws in communication technology from Morse code to the Internet. He proved that Marconi’s gear was insecure and it was likely that they could eavesdrop on supposedly private messages too. He justified his actions on the grounds of the security holes it revealed for the public good. It turned out he was hired as a spy for the Eastern Telegraph Company which worried Marconi would stuff up its business.
Source: https://thehackernews.com/2011/12/world-1st-hacker-exploit-communication.html