From the story on youtube and from what I gather, music was too loud, cops responded to a complaint and proceeded to arrest the guy...
I understand he resisted arrest, but seriously, what kind of society do we live in where when there's a NOISE COMPLAINT for a business (the guy's clearly at work) and the cops decide to arrest the guy? Even if he's being belligerent or hard-headed, aren't the police supposed to be able to deal with that? These people represent the law and the government; no patience at all in dealing with people? No, let's just arrest him instead. Obviously the guy's going to resist being arrested over a noise complaint, but to make matters worse, when he doesn't comply, they beat the shit out of him.
When you see ALL the people there angry at the police and what they did in this situation, you know that something's wrong... These aren't hippies or anarchists, these are regular people.
I have nothing against the idea of law enforcement or the police; they are an essential part of any society. That being said, the way the SPVM has conducted itself in the past few years has done nothing but tarnish their reputation; whether it be arrests like this (or those during the student protests), or the millions of useless tickets they've given to the population for harmless infractions, they've ruined their credibility as a force there to protect the island.