A lawyer once used AI to write a legal brief and submitted it to court. The brief cited six previous court cases as evidence. There was just one problem: none of those cases existed. The AI had invented them completely: fake case names, fake dates, fake rulings, all presented with absolute confidence.

The lawyer was fined. The judge was not amused. And the story made international headlines.

This wasn't a bug or a glitch. This is something AI does by design. It generates the most likely next words, and sometimes the most likely-sounding words form a complete fiction. AI doesn't know the difference between true and false. It only knows what sounds right. Learning to spot these "hallucinations" is one of the most important skills you can develop.