I don't think it's that simple. From my experience, if you are in certain non-Microsoft applications and the mouse is moving it will still set you as Away and won't set your status to Available until you click into an application it recognizes.

Reminds me of a story I read - some company had a batch job that ran for hours and for some reason if the computer went to screen saver, the batch job crashed and had to be restarted. Rather than actually find the root of the problem (of course), or disable screensaver (not allowed per security policy), they just assigned somebody to move the mouse every few minutes to keep the screensaver from activating.

So one day, the guy brings in a vibrating baby bouncer, puts the mouse in the baby bouncer, and kicks back for the rest of the day.

Many (most?) companies that care to track your productivity in invasive ways will have security policies locking out USB devices.

Even plugging in a charging cable at my company will get you a visit from the IT Security department.

I've found having a youtube video, like 10 hours of black-screen open prevents my laptop from logging out. Not sure if that applies here though.