I get the feeling waaaay too many people just bought a new trackball mouse instead of opening it up and cleaning it
...course in high school there were issues where kids would steal the balls, rolled em around in the halls and during class, competed to see who could get more without the teachers finding out, and the school eventually...well, I don't actually remember what they did anymore, it wasn't the kids in my year that were the issue and I wasn't the most sociable at the time, but it stopped VERY suddenly so something they did must have worked, then the next year they must have wanted to avoid a repeat cause we suddenly had shiny and very expensive (at the time) laser mice instead and there were constant inspections to make sure those didn't go missing