The monitor didn't turn off when Elias pulled the plug. The glow only grew brighter.
Sometimes, the xlive.ini file is set to "disable=0" by default. Open the file in Notepad and change it to "disable=1" to force the offline mode. Xlive.ini Download
Once installed, you can open xlive.ini with Notepad to tweak settings. A standard configuration might look like this: The monitor didn't turn off when Elias pulled the plug