David Lightman accidentally hacks into a super secret government computer, but his original goal was to hack into the computer of Protovision Inc. in order to access games that won't be coming out until Christmas that year. While he wouldn't be distributing the material, he was still getting for free what other people would have to pay for, and is also getting access before everyone else gets access. From an Act Utilitarian perspective, he wasn't casuing any harm by getting access to an unreleased game for free. The benefit would only be to himself, but he seemed to really want to play the games, so playing the game wouldn't be a bad choice. However, the method with which he would be able to access the game involves calling thousands of phone numbers in a particular area. While this doesn't cause a high magnitude of harm, the harm is widespread. He may interupt the day of hundreds of people by making them answer their phones to no caller or just leave it ringing. Either way the negative impact is very minor, so, while his choice may be selfish, it may still be considered a right choice from this perspective.
David Lightman discovers that new games are coming out from Protovision in a magazine, and uses the area code to narrow down a search of systems to dial into.
Taking a look from a Rule Utilitarian perspective, if everyone played unreleased video games for free, the benefit would be some fun for the all of the gamers. However, this would result in significantly less people paying for the games, making it less profitable for game developers to develop games, which would make them stop producing games. If the developers stopped releasing games, everyone else would have no new games to play, creating a contradiciton as you can't play new unreleased games if there are no new games. This makes it a wrong choice even without mentioning the significant harm that would be caused through the process of hacking into the Protovision computer. If everyone set up their computers to autonomously call several thousand phone numbers everyday, this would result in an overwhelming increase in spam calls which would cause people to not answer their phone as much expecting calls to be spam. If people stopped answering their phones, that would defeat their entire purpose as a communication tool. Obviously, this all ends up causing significantly more harm than good and is thus a morally incorrect decision.
As this film revolves around a WOPR, a government supercomputer in charge of determining responses to nuclear attacks, there were no apparent trademarks, copyrights, or patents. The biggest thing that would resemble a trade secret is the backdoor password "Joshua" that the original creator included unknown to the current agents. David was able to discern Dr. Falken's backdoor by studying publically available materials about his life.
[1] YouTube, WarGames, 6 Jan. 2020, www.youtube.com/watch?v=HNLQ-O-Qx3Y&t=1779s&ab_channel=YouTubeMovies (20 Sept. 2021)