A recent plea for help on Hacker News has reignited a fundamental conversation about software’s failure to handle human identity with nuance. A user, verified by Facebook with both a first and last name via official ID, attempted a name change. Facing a mandatory last name field during the process—despite their circumstances—they entered "No last name - disowned by family." The system accepted it verbatim, locking this intensely personal statement into their public profile.

This isn't merely a quirky bug; it’s a textbook example of software enforcing brittle assumptions about human identity. The user explicitly pointed to Patrick McKenzie’s (patio11) seminal 2010 essay, "Falsehoods Programmers Believe About Names", as the root cause. McKenzie’s list, including falsehoods like "Every person has exactly one canonical full name" or "People have last names, family names, or anything else which is similar," directly predicts this failure.

"Systems which do not allow for the fluidity of human naming inevitably fail their users in ways which are at best comical and at worst cruel."

For developers and product managers, this incident is a stark reminder:

  1. Mandatory Fields Breed Workarounds: Forcing users into arbitrary constraints (like requiring a last name) guarantees invalid or harmful data entry. Users will find a way to satisfy the system, even if it misrepresents reality.
  2. Verification != Validation: Successfully verifying an ID doesn't mean the underlying data model (first + last name) is valid for all future interactions or identity states.
  3. Edge Cases Are Human Cases: Situations like family estrangement, cultural naming conventions (mononyms), or non-Western name structures aren't rare exceptions; they represent real people consistently failed by inflexible software.

Platforms like Facebook, handling billions of identities, face immense scaling challenges. However, this incident highlights how deeply ingrained cultural biases and technical shortcuts—like assuming a two-part name structure—perpetuate exclusion. While Facebook likely aims for simplicity, the cost is borne by users whose realities don't fit the mold. Solving this requires moving beyond rigid schemas, perhaps embracing free-form name fields, structured but optional components, or explicit support for mononyms—design choices advocated for over a decade.

The user's unintended "No last name" identifier is more than a glitch; it's a monument to the industry's persistent oversight. As long as software clings to naive assumptions about names, it will continue to tell users, quite literally in this case, that their identity doesn't compute. The solution isn't just fixing one user's profile; it's architecting systems that embrace the beautiful, messy complexity of human identity from the ground up.