I work on a university campus. The highlights:

Riding against traffic on sidewalk
Riding against traffic in bike lane
Riding on marked "no bicycles" paths (many are too narrow to accommodate pedestrians and bikes)
Blowing through red lights/stop signs/crosswalks
Riding bikes INTO and THROUGH the building (I'd think common courtesy is to walk it if you're going to take it in)
Ninja cycling
Texting/talking on phone while biking


As a side note - a few of the sidewalks on our campus are too narrow to contain pedestrian traffic during class change times, so people walk in the bike lane. How annoying is that? I know this thread is cyclists behaving badly, not pedestrians behaving badly, but just wanted to vent Peds in a 4-block radius from my office cause me more grief than all the cars on my 8-mile commute combined.