If you didn't see it, a visiting outfielder was catching a deep fly ball when a Cubs fan, timing for when the ball arrived, dumped a beer on the outfielder. Security then ejected a bunch of fans, but at this writing it's unclear whether the guilty party was thrown out.
You can see the clip here. The fan clearly endangered the safety of the player. What throughly depresses me, though, is that when ESPN asked its readers whether they would turn in a fellow fan who did this, a whopping 27% said no.
I wouldn't have thought it possible for me to think even less of my species, but here I am.