Most of these things are done by the snotty kid with a smile because he knows he's getting to the other students and the teacher.  This is a temporarily satisfying feeling to the child. The child may feel, after all if he or she has to be in pain, so should everyone else!  Why should he or she be the only one hurting?

Nine times out of ten, this bane to everyone's existence is hurting and suffering.  This kid is sad and lonely and angry at the world.  You often find they have well-meaning, yet unattentive parents or in the worst case scenario a horrific home life. Sometimes the only time they feel like they exist is when they are hurting others and getting reprimanded for it.  Negative attention is better than no attention, right?

These kids often grow up to become sad and bitter adults and these sad and bitter adults often find a psuedo social life on the internet. On the net they have an even bigger voice and an even larger venue to pester others.   The internet gives them the opportunity to say things behind the safety of their computer monitors and anonymous handles that they know they wouldn't have to testicular fortitude to say to someone in real life. The sad thing is that these people are still in pain, still suffering, still have poor social skills and are still angry at the world.  They haven't developed the ability to positively confront their pain and overcome it. Instead, they've fallen back on old habits; picking fights, making snide remarks and proclaiming that everyone else is an idiot.  It's hard to ignore these people. I know it's really hard for me to ignore them, because while I have patience beyond patience with children, I have absolutely no patience with childish adults.  However, ignoring them is the best way to demonstrate that you understand that their need to annoy others and their need to say something offensive is their way of acting out.  It's the virtual temper tantrum and as most parents and teachers will tell you, the more you pay attention to a tantrum, the worst it gets.