We all know that cyberbullying is a horrible thing to happen - but now it seems it's not just kids that are being bullied online.
New research has found that lots of school teachers are getting bullied by their pupils, and sometimes even parents of schoolkids too.
A university report spoke to hundreds of teachers and found that more than one in three had been bullied online, or seen it happen to another teacher.
We want to know if you've seen this happen. Have you ever known of a teacher getting bullied on a website or social network? What happened about it?
Thanks for all your comments. This page is closed now but you can read some of your comments below.
"I've seen parents, teachers and headteachers getting photographed and posted on facebook without their knowledge. They don't really do it to make fun of them just to get a kick out of it."
Praveen, 13, Cardiff, Wales
"It is so sad to think that people are being bullied online. And now not only children but teachers as well!"
Meg, 10, Singapore, England
"I think this is horrid. No one deserves to be bullied, ESPECIALLY by their own pupils!"
Faatimah, 10, Kirklees, England
"Well I have never heard of this, I have seen my friend search teachers but never anything like this."
Megan, 11, Cheshire, England
"I think bullying teachers is wrong because they could contact your parents, expel you from school or phone the police and get you in serious trouble. I like my teacher and would never bully her, and who would want to bully an adult anyway?!"
Melissa, 10, Berwickshire, Scotland
"Maybe these teachers feel they cannot tell anybody. It's always said that children being bullied should tell an adult they trust, for example a teacher. Who would they tell? Would it make them feel "silly" or "dumb" or "weak" if they were bullied by younger students?"
Cleo, 14, London, England
"Teachers always tell us to be safe on the internet, but why don't they do what they tell us and try to be safe?"
Tamzy, 12, Cheshire, England
"It's unfair because they are taking their time to educate us, sometimes parents can be a bit defensive but they shouldn't bully teachers. I know a teacher who has been bullied online by a parent that I know, and the teacher was upset and kept it to herself. It wasn't fair to her."
Annabel, 14, Dudley, England
"I've never seen anyone bullying a teacher, but some people write some pretty mean stuff about them online."
Chloe, 13, Pays de la Loire, France
''It's not right, it's bad enough for kids! You should get a fine or something."
Dina, 9, Swansea, Wales
"I think it is horrible because adults don't deserve to be bullied!"
Sarah, 7, London, England
"I've never heard or seen a teacher being bullied. If they are it's just stupid and wrong!"
Kimberley, 12, Birmingham, England
"It isn't good for anyone to be bullying anyone else. We should respect teachers because they prepare us for our future. Pupils shouldn't be bullied either because it's not right. I like my teachers because they make an effort to help us."
Rachel, 11, England
"I think a teacher getting bullied is a horrible thing to do and it should be illegal."
Lauren, 7, Sussex, England
"I never saw a teacher get bullied, I wonder how it feels for them."
Caner, 10, London, England
"I think it's impolite to bully teachers because they are older than the students and they have given their knowledge to us."
Claudia, 13, Jakarta, Indonesia
"I've personally never heard of anyone "bullying" teachers. I understand that sometimes parents put a lot of pressure on teachers but this possibly isn't defined as bullying. The word "bullying" implies a situation where an individual is being made to feel belittled, so though we associate it with younger people, there is no reason why it might not happen to adults. Perhaps we just hear about it less since teachers feel like they can't report it. They are the ones other people turn to when they need advice and assistance with bullying, so many may keep quiet since they feel they have no one to talk to."
Mackenzie, 14, London, England
"It isn't right for anyone to bully anyone else. In my opinion people have lack of respect towards teachers and show no empathy. One day the students and their parents will look back and thank the teachers for all their support and effort. I love my teachers!"
Nadia, 13, Bali, Indonesia
"Why would a teacher be bullied online? Only teenagers are bullied online."
Yasmin, 7, London, England