It's not on that wikipedia page but in older Linux desktops using XFree86 windows system (before X.Org) there were always warnings that certain monitor settings could break your monitor hardware permanently.
I was always fearful of breaking an expensive fat monitor.
It was absolutely possible to fry old fixed-frequency monitors by specifying an improper HorizSync in your XF86Config.[0] Fortunately, for most of us fixed-frequency CRTs had been largely replaced by more modern multisync monitors[1] before we were out of diapers.
