it happens to me all the time with a colleague that sits in front of me. every time he stand up, my monitor start glitching.
i found that cause a couple of weeks ago, and now i find it hilarious
> Turns out that some joker pulled out two keys from the keyboard and switched their places. [...] They were both relatively good at typing and didn't look down at the keyboard when typing when sitting. But typing when standing is something they weren't used to and had to look down at the keyboard which made them press the wrong keys.
Once in college, somebody thought they'd be clever and remove all the keytops on the only CRT in one small timesharing computer lab. Didn't bother me, because I was a touch typist - didn't need to see the keys at all.