Dunno what made me think of this just now. When I worked for IT in a school district way back in the 90s, a librarian told me she kept a supply of mouse balls in her desk because kids would steal them out of the school computers. What I remember about those balls was they picked up dust and crud off surfaces. Pretty soon optical mice came along and they were history.
Man, that’s a blast from the past! I had completely forgotten about that until I saw this post!
I wouldn’t say I ‘stole’ them necessarily. But me and my buddies did used to take them out and hide them near the desks as a prank.