Bullying

These days many kids and teens are being victims of the many forms of bullying: cyber bullying, physical bullying , verbal bullying... 

The bullied often have no one by there sides. In addition, if it's verbal bullying, they may believe that whatever the bullies are saying is true, which can lead to anxiety. If it's physical bullying, they'll be too afraid to tell anybody and will end up being used to being hit. Furthermore, i think cyber bullying is also very dangerous, you can be threatened by someone you don't even know and not be able to define why this person is bullying you.

Finally, if someone ever has the courage to tell you that he's being bullied, immediately try to help him and tell an adult.