When I saw this license plate, I thought "Cool, they've been doing this for over twenty years!"

But then I realized that an assumption I'd made was definitely wrong.

What was my original assumption and how did I realize it was wrong?

In college, I lived in cooperative housing. The idea of a cooperative is that the members run and co-own it, contributing money (rent) and time (chores), and decisions are made communally. Which sounds not too different from any shared living situation—except that there were over 120 students in the house I lived in, 1000+ in the parent organization, and the organization was able to save its members a lot of money because it owned its buildings and bought supplies wholesale.

Anyway.

One day I was riding BART home from a demonstration (it was early 2003, people were protesting the Iraq war) and someone handed me a bumpersticker that said REFUSE EMPIRE. I was about to hand it back for lack of a bumper to stick it on, but then it hit me that I knew exactly where to put this sticker. I went home and stuck it on the wall in a particular area of my co-op, an area where I spent a lot of time because of my assigned chore. What was that chore?

Solution

I was in charge of trash and recycling (my official title was Czar of Offal Attrition). REFUSE EMPIRE looked just right above our bins.

(Favorite wrong answer: Replacing fuses in the fusebox.)

Congratulations to yesterday's solvers Ian, Leo S., Peter V., Peter M., Charlie, Jacob C., Dr. Hill, Dr. Yetman, Kate, and Zachary S. Thanks to everybody who made a guess!