In the late 80's I worked as a system engineer for a large automobile firm. I maintained the CAD/CAM system. The system used pens and tablets. The system was very subsceptible to static electricity, and pens were changed on a fairly regular basis. One day, a new designer started, and immediately needed a new pen. I replaced it, and a few hours later, she needed another. For the next week, I replaced pens about twice a day, sprayed with anti-static, and tried everything I could think of to no avail.
Then I noticed that she was wearing a wool skirt. I had to politely ask if she was wearing silk underwear. She was!! Every time she squirmed or moved in her chair, she was generating static electricity. Enough to damage equipment!!