There's a famous Raymond Chen post about how a non-trivial percentage of the blue screen of death reports they were getting appeared to be caused by overclocking, sometimes from users who didn't realize they had been ripped off by the person who sold them the computer: https://devblogs.microsoft.com/oldnewthing/20050412-47/?p=35.... Must've been really frustrating.

This was a design choice by AMD at the time for their Athlon Slot A cpus. Use the same slot A board which you could set the cpu speed by bridging a connections. Since the Slot A came in a package, you couldn't see the actual cpu etching. So shady cpu sellers would pull the cover off high speed cpus, and put them on slow speed cpus after overclocking them to unstable levels.

E.g., running a Pentium 75, at 75MHz.