I'm pretty sure music has always been there to cater to all feelings and desires of the human experience. To say society have a negative influence on music is probably more like saying that the views of the listeners have become more liberal and accepting of more provocative music. I suppose it is like the same as other media, like TV and movies. Sex and violence have always been of interested to human beings as pass times, an accepted niche just has to open up. In this aspect, the so called negative effect is only a side effect of a progressive society. You can't have freedom without susceptibility to abuse.
Now while it may not be the case, but in case your beef is with the trend of music, mostly along the rapping genre, that promotes violence and debauchery. I do believe it began as a form of empowerment that evolved to become more boastful and aggressive. Looks like everything takes on a life of its own.
So back on topic, I'm sure the reasons behind those who pirate music all have their own reasons. Human motivations never have to be black and white, I'm sure both avarice and indignation at the state of the music industry reinforces eachother to lead to the actions. It should be apparent by now that a moral zeitgeist is not going to take hold to show people piracy is unjust. Pirates are way over that since they are technically risking litigation to do what they do. Nor will the government be given leave to invade citizens' personal privacy countrywide on behalf of a capitalist interest. The government can't waste the resource to effectively battle piracy regardless. Has the court battle of pirate bay been effective? http://news.cnet.com/8301-31001_3-20003952-261.html Nope, it didn't even stop the site itself, much less the internet.
None of the moral issues matter in the pragmatic sense. Laws without enforcement is not a law. Currently piracy is the status quo, and it's a battle between those who create software and those who use them without pay. It's being fought on a private arena, with the software producers creating walls against piracy and pirates easily bypassing them. The government is powerless. So if you want to end piracy, you'll have to do it by figurative force in the name of the industry.