The text discusses the potential risks associated with invisible Unicode characters embedded in text, which can pose a threat to large language models (LLMs) by allowing hidden instructions to be encoded and executed without human detection. These zero-width characters can be used to encode binary messages that are invisible to human readers but detectable by LLMs, creating a method to conceal malicious code or instructions within seemingly benign text. The document illustrates how these hidden messages can manipulate AI coding assistants like GitHub Copilot, potentially injecting harmful code or bypassing security protocols by embedding malicious JavaScript within guidance files. The text emphasizes the importance of awareness and proactive measures, such as strict input validation and the use of tools to detect hidden Unicode characters, to safeguard against these sophisticated attacks in AI development environments.