Disable accessibility options in Windows 8

Does anyone know if it's possible to fully disable accessibility options for Windows 8, or at least make it so they cannot be accessed from the lockscreen? Basically, I'd like to make it so my roommates can't mess with the settings when I lock my computer.

I always lock it when I leave it alone, so they turn on accessibility options instead of posting on my Facebook or changing my homepage. I'd like to stop them.