When your input validation finds a null value and decides the appropriate punishment is making the thread sleep for approximately 115 days. Nothing says "robust error handling" quite like passive-aggressively freezing your application because someone didn't fill out a form field. The comment "Punish user for null" is chef's kiss – like the developer is some kind of vengeful deity dispensing justice through Thread.Sleep(). Sure, you could throw an exception, log it, or display a helpful error message... but why not just commit application seppuku instead? Your users will definitely appreciate the 9,999,999 millisecond timeout while contemplating their sins of poor data entry.