Back when U.C. Davis (the old University Farm, 60 miles up the road from Berkeley) had more bikes coming to campus than could be accommodated near the classrooms, the campus cops would just impound the illegally parked bikes. The only "fine" for first time offenders was that they had to pay for a bike license (technically required to park a bike on campus). It was something like $15, which was a lot when quarterly fees were only $275 and most students worked part-time jobs to pay all their college expenses.