Cranking it up for a good song is one thing, but that's not irresponsible. These guys that have sound systems that you can hear the base from a mile away and are not one iota mindful of the time or location are the ones who get on my nerves. They couldn't care less if they are bothering other people, and sometimes I think that is the intention.
They have the dumbest of the dumb yelling into the megaphones and leading the other dumbasses.