1) The Y2K Bug

This bug is perhaps the most infamous in software history due to its widespread impact. It originated in the 1960s and 70s when organizations began relying heavily on software but were constrained by costly memory. Developers often abbreviated years to two digits—thus, “1989” became “89.” As a former COBOL programmer recounted, resources were so limited that every byte counted, and there was an assumption that systems would be updated within a few years.

As it turned out, these legacy systems persisted well into the late 90s. When the year 2000 arrived, many systems interpreted “00” as both 1900 and 2100. Consequently, banks could mistakenly attribute decades of interest to customers’ accounts.

The takeaway? We often underestimate the longevity of our code and the importance of considering how our creations will function in the distant future.

This video, titled Everything You Wanted to Know About Y2K but Were Afraid to Ask, explores the intricacies and implications of the Y2K bug.

2) A Single Character's Catastrophe

On January 31, 2009, Google users encountered a peculiar issue: every search result bore a warning stating, “This site may harm your computer.” The culprit? A minor error in an update to Google’s malware file. An engineer inadvertently included a single character “/,” which led Google to mistakenly flag every website on the internet as harmful.

This incident highlights the unforgiving nature of coding syntax; even a single misplaced character can have significant repercussions.

The video titled The Y2K Millennium Bug 20th Anniversary - Was It a Real Danger? examines the perceived threat and the actual outcomes of the Y2K bug.

3) The Morris Worm Incident

On November 2, 1988, Robert Morris, a computer science graduate student, released the first worm that spread globally. Unfortunately, it contained a serious bug that led to widespread chaos. Morris's intention was to demonstrate the lax security of early internet systems, but the worm was designed to replicate itself in a way that caused it to infect systems at an alarming rate.

This incident taught us that networked systems are intricate and that bugs can escalate quickly, yielding unforeseen consequences.

4) The "Coke" Bug

A humorous yet enlightening bug involved a financial-compliance application that crashed whenever a user went to get a Coke. This peculiar behavior stemmed from the application logging users out after 15 minutes of inactivity. The user found that their trips for Coke, which took longer than coffee breaks, led to unexpected logouts.

This illustrates that bugs can arise not only from the code itself but also from how users interact with the software—often in ways developers did not foresee.

5) The Mars Climate Orbiter Mishap

In 1999, NASA launched a probe intended to orbit Mars, but it tragically disintegrated upon entry. The cause? A misalignment between the metric calculations used by the navigation team and the imperial measurements employed by the engineers who built the craft. This oversight was only recognized post-launch, serving as a stark reminder of the importance of aligning both software and data assumptions.

6) The "Corrupted Blood" Outbreak in World of Warcraft

On September 13, 2005, an update for World of Warcraft introduced a new boss, Hakkar, who could infect players with a debilitating disease. While the developers intended for this infection to remain confined to the boss battle, players found a way to carry it back to the broader game, resulting in a massive in-game epidemic.

This incident demonstrates the unpredictable outcomes that can arise from tightly connected systems, especially when influenced by human behavior that defies the original design intentions.