Over the years of troubleshooting performance problems in the Unix/Linux world, I have seen multiple cases where a regularly used command line tool in a customer server just stops working for some reason. The tool just returns immediately, doing absolutely nothing. No output printed, no coredumps and the exit code is zero (success!).
This article walks you through a couple of such incidents and in the end I explain how I avoid accidentally doing bad stuff in production in general.
Source: Do Not Use '>' in Your Command Prompt (and How to Stay Safe in Shell), an article by Tanel Põder.