We're bullied by parents, by students, by our fellow teachers, by administrators. It's pervasive, and honestly, it's not that surprising that students are bullied and that many look the other way when you look at what's going on with the adults.
I've had parents get in my face and scream at me, call me at all hours to call me all sorts of names because their kids weren't getting As in my class; students threaten me with everything from getting me fired to killing me and then nothing happening to the student; fellow teachers isolate me (mostly in my long-term sub gigs) and refuse to work with me simply because they were angry that a long-term sub was hired instead of one of them getting the job; principals tell me that I can be replaced the next day and harass me to the point of health problems . . . You name it, I've seen it happen either to me or to a fellow teacher.
It's something the union's supposed to help us with, but if you can't be a union member (and subs can't be here), well, then you're screwed.