In some places I've had to use remote KVM extenders, which are HIGHLY susceptible to ESD pulses from office chairs. A few times every hour the screen blacks out for a second, usually returning to normal, just because someone stood up.

Apparently so are HDMI cables. A HN thread few months ago clued me in on this, and this solved a weird issue I had with my work laptop: it would randomly bluescreen; at first, once a month, but after a year it was closer to once or twice a week. There was no obvious pattern to it, except it almost always happened within a minute of me getting up from the chair. I suspected it was overheating, but ensuring it's cooling properly didn't help. The problem went away when I stopped using and actually unplugged the external display, and now it seems very likely it was the cable picking up ESD from the gas piston of my office chair.