Bullying Again

So there's this popular new viral video...of a twelve year-old kid attempting to bully a bigger teen kid. 12-year old punches teen in the face, teen body slams him onto the curb, 12-year-old apparently gets broken leg.

A part of me says that we shouldn't fight...

but another part says he deserved it

Because I'm sure a lot of us know, that if we fought in school, we got at least a detention. But bullies don't learn their lesson, so HOW are we (or kids) supposed to defend ourselves from bullying such as this?