Caught on Tape: Shocking Teacher Meltdowns Alleged misdeeds by school teachers used to be a case of "he said, she said," but these days tech-savvy teens are increasingly turning to their cell phones and other tools to expose instructors who are acting classless in the classroom....and getting payback when the teachers have to answer for their behavior. A number of videos depicting just that have gone viral on YouTube and made headlines across the country. Charles Fay, Ph.D., a psychotherapist who works with educators, said some teachers -- particularly special needs teachers -- are vulnerable to losing self-control. They have the hardest job in the world. They are dealing with kids that have been hurt. They are dealing with kids with special neurological issues. They are dealing with a whole host of baggage this kid, these kids bring in every day," he said. By and large, they are doing a fabulous job. But if you don't have the skills, or if you don't have the right attitudes, that's going to wear on you like water torture," Fay said. Experts say teachers aren't always to blame: students sometimes provoke teachers on purpose just so they can record ensuing tantrums and post them online later. It's called "cyberbaiting" and can result in devastating consequences -- including job loss -- for the teacher. Check out these five shocking teacher meltdown stories and watch "Payback" on "20/20" Friday at 10 p.m. Special Needs Student Threatened With 'Kick Your A**' Julio Artuz, a 15-year-old New Jersey special needs student, recorded his teacher telling him he would "kick your a** from here to kingdom come," last October. Artuz's parents originally thought their son was lying when he told them that his teacher had subjected them to verbal abuse -- their son's cell phone video quickly changed their minds. "You're teaching the kid how to curse, you're teaching a kid how to be a bully, you're teaching everything that's wrong," Artuz's father, Julio Artuz, Sr. said. Julio changed schools and the teacher was later fired, but the teen says he now misses his friends and copes with bouts of depression. "Everything that my son worked for has just been cut off, back to square one," Artuz, Sr. said. That's not right. Watch the video here. No Wonder Nobody Likes You Another special needs student found herself under verbal assault last fall at her Ohio middle school. Audio recordings made by a 14-year-old named Cheyanne show a teacher's aide calling the girl "dumb," "lazy," and a "liar." It's no wonder you don't have friends. It's no wonder nobody likes you, because you lie," the aide says on the recordings. The recordings also catch Cheyanne's teacher announcing that the girl bombed a test without even looking at the girl's work. You failed it. I know it. I don't need your test to grade. You failed it," she said. After the recordings were played for school authorities, the aide resigned and the teacher took unpaid leave for a year. Cheyanne felt relief when the truth came out. The teen now attends high school and is enjoying her classes, her parents said. "She says that there's no problems," her father told "20/20." The first complaint that we do get, I'll send a recorder. Teacher Handcuffed, Taken Away on a Stretcher An 11th grade student taped his algebra teacher yelling and throwing furniture in his Nashville, Tenn. classroom in October, 2010. Several students ran out of the classroom but no one was hurt. The male teacher was handcuffed and taken out the school on a stretcher. After the incident, the teacher's sister said he appeared to have suffered a nervous breakdown. The teacher was placed on administrative leave and received psychiatric treatment at Vanderbilt University Medical Center. The Metro Nashville school board recently decided to take steps to dismiss the teacher, according to The Tennessean newspaper. The teacher has not yet announced whether he will appeal the dismissal. Teacher Punches Student A cell phone video taken last May shows a female Florida art teacher warned an unruly male student to "step back" before punching him in the face. Witnesses said they saw the student touched the teacher first and law enforcement authorities decided not to charge the woman with any crime, saying the video didn't prove that the teacher wasn't acting in self-defense, The Tampa Bay Times reported. "You couldn't put a piece of paper between them," Brian Trehy, of Florida State's Attorney's office, told the newspaper. You can't tell if he actually made contact, but it's certainly reasonable to believe that it could have happened. Student Kicked and Slapped Texas teacher Sheri Davis was shown kicking and slapping a 13-year-old student for nearly a minute in a video taken by another student at a Houston charter school in April, 2010. In an exclusive interview with "Good Morning America," Davis said that, at the time, she was trying to defend another student and had had her adrenaline pumping after breaking up a fight that happened minutes earlier. These kids are just, basically, laying around on the floor, just being hostile. And this young lady was in the middle of the floor. The door was locked shut and the kids were there, kind of mimicking her. This particular young man, Isaiah, was bouncing around in a threatening, bullying position," Davis said. I have adrenaline that is already building up with the fight that just happened minutes before. Davis said she and other teachers were not properly trained on how to handle students at the school. The school denied the allegation, saying that nothing like the Davis incident had ever happened before. Davis, who had been named the school's teacher of the year twice, was fired after the attack and was charged with injury to a child, a third-degree felony. She pleaded no-contest to the charge, was sentenced to five years' probation and ordered not to work as a teacher during that period, The Houston Chronicle reported. Watch "20/20: Payback" Friday at 10 p.m.