Just didn’t really occur to me that this is an issue. The offices I’ve worked in here in Norway, most people just do their part to keep the coffee machines orderly and clean. We had mold once when we forgot to empty the filter before the Christmas holiday, but first person in the office emptied it, cleaned the filter holder, left it in a mix of water and vinegar to kill whatever was left, and a couple of hours later (9 o’clock ish) we were brewing coffee again.