Piracy contributes to ecology. I have tons of worthless plastic cds and boxes and I know people have even more but don't even use them cause everything is on the hard drive. Now who's gonna recycle that?
I think that the change that piracy made in music industry is that most artists profit more from concert fees than selling records. This may not apply to the big names but generally it's like that when it comes to the local scene. And I guess it's all right to share your own records for free, I do that.
As for software, I really like how open source/free software movement counteracts both piracy and the Microsoft monopoly. Why should I buy MS Office if I can pirate it, some say. But then why should I download it when I can get Open Office that's way better and free. Professional software piracy isn't a problem, I guess, if a kid downloads AutoCAD, messes with if a little and gets rid of it cause he can't use it, it's no problem, and pirating software in a real company won't work cause you always have to document where the software comes from. With games, I guess that top games with huge graphics that require lots of work shouldn't be pirated, Im as satisfied though if I play a simple yet puzzling game someone made and distributed for free. I guess that games should be 'abandonwarized' earlier so you can freely distribute them. I guess that most profit is generated when the game is new anyway.