I defended myself from bullying with different methods at different times of my life. Nowadays, I don't have the problem at all, although I still don't have any idea of what they say of me outside of school.
In the middle school, I was a bit of a wackjob. At that time, I just got fed up with the bullying and I started to beat people up, beginning with my bullies. And mind you, I did not just use my fist to do it! I remember being in the counselors offiice and I was reading a book on how dictatorships would exploit a person's phobias for interrogation, and with the way my mental condition was at the time, I read it too soon. Bullying soon stopped, but I was then intoxicated with power and I grew more and more paranoid of other people. I was soon moved away from the school by order of my psychiatrist and psychologist and put under extensive medical care.
In the high school, I was never bullied. I attended a school for kids with ADD, Autism, Dyslexia, etc, for a time. I went back to public school, I was still never bullied, though I was still not anyone's favorite person. However, I developed what some would call an alter ego out of the desire to never again have to experience bullying (I'm a very unpleasant or intimidating person inside of school). I can still be a little paranoid but nowadays I can function normally in society. I also have a good number of friends, outside of school of course .