I'd guess they're being affected by the same bug, although not precisely at the same time. If everything freezes it's not necessarily anything to do with the mouse, that's just the first thing you notice.

What's your operating system, and do you have any security software?
Is there any correlation with the software that's loaded at the time, even if you're not actually using it?
Anything unusual shown on the lights? Like continuous disc or ethernet activity (although you may not have specific LEDs for these, cursed be the manufacturers who dropped them)?
Can you do a normal restart or do you have to force a power down?
Is your router set to allow any sort of remote access?