I always have 1 cat on my desk, one playing with the wires under my desk. So it is always either random typing, or unplugged wires.

That has happened to me more than once... In fact, I have had the cat not only type, but open Skype and place calls to family members, all through "creative reclining" on my keyboard.

I try to remember to lock my computer when I'm not physically present at the keyboard now.

My cat is able to find the most esoteric keystroke combinations ever thought up by Ubuntu developers to change my configurations ....