Definitely isn't brutality, it is excessive force if anything. The kid was probably flipping out and being cocky and they had to make an arrest, so they had to tase his ass...
If you resist arrest, you have to deal with the penalties. If he was smart, he would've gotten on the ground and lied there until they cuffed him, and then see if they were brutal. That is what you have to do, if you're confronted by police and you know you're in the right - fall to the ground with your arms and legs spread, and make them look like morons.
