Uh, I'm not argentine, hope I'm not giving that impression
I guess it's a bit being a big city, where police doesn't have any real power, mixed with constant ups and downs of economy and government controls. What I hear from people it wasn't always like that and I can see the difference in older generations.
Of course, noise issue could be solved instantly, if there would be will to respect the law. It's the easiest to detect, after all. Too loud moto, 2000p fine or moto taken, roof party, few thousand pesos fine to the owner of facility, loud music in department, the same... and I guarantee half of noise would dissappear.
But, as they usually say, we don't want to have strong police, because it was problem in diktatura,so now they have diktatura of criminal and irrespective people... Everyone gets, what deserves (not necessary want, mind you).
