The videos started popping up last month on YouTube.
In one, secretly videotaped by a student, a teacher at Malibu High School loses control of the class and raises his voice while students laugh at him. In another, teenagers make fun of fellow students, who also appear to be taped without their knowledge.
The videos have roiled the high school and sparked a debate among students, parents and administrators about what to do. The Santa Monica-Malibu Unified School District started by restricting access to YouTube at school and talking about what types of technology -- such as digital cameras, personal digital assistants and laptops -- students can use on campus.
YouTube, MySpace and other websites are sprinkled with videos taken in high school classrooms around the country -- often, it appears, without permission of the subjects. Many are relatively tame -- others not. One popular YouTube video called "The Angry Teacher" shows a male instructor increasingly losing his cool to a classroom of unruly students. Another shows an agitated teacher pulling a chair out from underneath a student.
But policing these secret videos is proving a challenge for educators, who say they must balance protecting the rights of students to express themselves in this digital age with the need to shield classmates and teachers from ridicule.
"It's a gray area for us," said Malibu High Principal Mark Kelly. "We want to recognize our students' free speech rights, but on the other hand we have to assess the educational impact to the students and our school. Is this going to disrupt the education process of the school day?"
Officials at Tesoro High School in south Orange County are dealing with the same question after students secretly taped a teacher on campus and posted it on YouTube.
The clip, which is 2 minutes and 22 seconds long, features video of a white-haired teacher walking around the Los Flores school, edited to accompany the lyrics of the Bee-Gees' "Staying Alive." The YouTube user who posted the video wrote: He "gave me a D in biology freshman year. [He's] a sexy beast. Who's laughing now!?"
Officials at Capistrano Unified School District said they were unaware of the video until The Times contacted them, noting that access to YouTube is blocked on all district computers.
Tesoro Principal Dan Burch said he was alarmed to learn that students were videotaping teachers on campus without permission, but added it was such a new issue he would need time to figure out a response.
"People's rights, in my opinion, are being violated," he said. "I don't know what I'm going to do about it. Frankly, it's the first that I've heard about anybody from my staff" being videotaped.
In Malibu, officials still don't know who took the videos. They didn't even know the videos were on YouTube until the student school board member told them about it and the Malibu High newspaper wrote an article about the controversy.
While students are not supposed to use their phones in class, the reality is much different.
"It's very easy to conceal phones and not have teachers notice," said Sarah Paxton, a senior at Malibu High and the student representative on the school board. "Most students will use books and then have phones in their laps, and they'll text message, or you can have a sweater covering [the phone] so only the camera shows. It's not that difficult, especially if the teacher is trying to focus on the whole class."
That's what happened on one of the videos, in which students compared a popular math teacher with an unpopular substitute teacher.
Malibu High math teacher Ruben Scott, who was depicted in the online video, learned about it from a student and had seen the footage on YouTube.
"In my particular case because it was an innocuous moment, I didn't feel particularly upset about it," Scott said. "But in principle, I was very upset. Teachers have enough problems as there is.... When I come into the classroom I expect to be exposed to my 30 students at that period, not to the world at large."
The classroom videos represent the latest headache for educators trying to police student misdeeds on the Web. Two years ago, school officials across L.A. were grappling with a website managed by a teenager, in which students placed offensive comments about classmates and teachers for all to see.
School officials in Toronto this month are considering a ban on cellphone use in classrooms and hallways after students taped several fights and posted them on the Web. In England, educators have tried to crack down on so-called "teacher-baiting," in which students purposely taunt a teacher and then capture his or her response on cellphone video.
"Cyber-bullying has been an issue the last couple of years," said Santa Monica-Malibu school board President Kathy Wisnicki. "Now with YouTube, we're just seeing the potential ways that it could cause a situation on our campus among students with teachers, and we're going to have to examine that."