USA vs. El Salvador Crowd Scene

This was in Baltimore which, the last time I checked, was in the good ol' USA. So what's up with these El Salvadorians trying to put a whippin' on red blooded Americans (or at least some what red blooded Americans?) on our soil? We gonna put up with that? Especially in the home of The Wire?

P.S. Is there anything more cowardly than the sucker punch that was delivered right after the :30 second mark? Well, maybe taking your belt off and swinging it around like madman.