Lightman calling to ask about Falken
Phone Calls
Lightman interacts with technology that connects him to information he otherwise wouldn't have been able to know. He learns of the company Protovision from an ad and utilizes his phone to access information about them. When Lightman tries to cut ties with the NORAD computer, it calls to reach him. Later he uses a payphone to make a call and find information about Falken [1]. Phone calls were an important means of communication for the time period as it was faster and easier to use than most other methods.
Spam
After calls Lightman Protovision's number for information, he then has his computer dial all the phone numbers in the Sunnyvale area. While dialing all of the numbers, he stumbles upon a number that won't let him log in. This number is what connects to the NORAD computer. [1]
All the phone numbers Lightman's computer has dialed
Self-Censorship
After Falken is presumed dead, he keeps the fact that he is alive and all of his contact information a secret to prevent anyone from finding him. Despite his efforts to keep his information hidden, Lightman still manages to find him [1]. Besides this instance, there aren't many cases of self-censorship as it mostly wasn't necessary. Since digitized records were nowhere near as common as they are now, there was little need to worry about personal information spreading quickly.
Lightman messaging the supercomputer
Messaging
Lightman is able to communicate with the NORAD computer by typing and receiving messages. The AI in the computer is capable of understanding what Lightman says to it and give a response.
[1] YouTube, WarGames, 6 Jan. 2020, www.youtube.com/watch?v=HNLQ-O-Qx3Y&t=1779s&ab_channel=YouTubeMovies (20 September 2021)