Yesterday, Occupy Portland mustered enough people to shut down three Port of Portland terminals for more than 12 hours—and it all happened with nary a substantial clash with police, despite the looming presence of a small cadre of riot cops throughout much of the day.

Other occupy movements in other cities didn't fare as well. Cops in Long Beach shoved protesters with batons to open port entrances. In Houston, protesters who blocked a road by tying themselves to PVC pipe were arrested after cops reportedly taped up their badges and set up a tent around them. And, after police in Seattle said they were hit with debris and paint, they dropped flash-bang grenades and may also have used pepper spray.

Which awkwardly brings me to the point of all this. So just how much of a break was it that Occupy Portland didn't also see pepper spray? A handy little graphic after the cut explains precisely why and how pepper spray is a pretty horrible thing to have misted into your face.