The entertainment business hasn't ceased to exist despite a decade of internet piracy -- and in fact seems to be doing quite well. Both of your examples, Adele and HBO (http://www.nytimes.com/2011/08/04/business/media/time-warner...) are doing great -- so I wouldn't hold them up as examples of the plight of the entertainment industry.
So, I'd ask you instead, how can you show that our existing laws that protect rights holders aren't adequate.
What many (most?) commentators fail to understand is that the entertainment industry is not interested in anything that account for less than 1% of the population. If 2.6 million americans wish to use some wacky "Direct Connect" or "Darknet" or "Unregistered Usenet" system - have at it. You are round off error.
It's when it moves into the wholesale category of piracy - ala: http://www.google.com/search?q=adele+mp3+download
Then they have a problem. As do the artists.
It would be interesting to see a study of "Health of Entertainment Industries with heavy emphasis on Content Resale" vs "Protection of Intellectual property (copyrights, trademarks, internet policing" in various countries.
HBO and Adele may be doing okay - how many thousands of artists can't make a living (and don't even try) - because they would be just ripped off.
Don't get me wrong - I'm opposed to SOPA, but not because I don't think it wouldn't help the entertainment industry - I'm certain it would. I'm opposed to SOPA because I care more about the internet industry (which SOPA would hurt).
At the end of the day - it's really a question of which we value more - creation of high-value entertainment content, or individual rights, freedoms, and the entire internet industry.
I know where my vote is.
This is the crux of the issue. I contend that more art is being created now than ever before. I know so many musicians in my personal life, I can't even keep track of all of their albums and shows. On SoundCloud and YouTube and Internet Archive I could listen to music freely given for months on end and never listen to the same song twice.
However, I have never once met a musically inclined person that decided not to make music because of GrooveShark or BitTorrent. I've never heard someone say "well, Adele is only worth 20 million, and I'll never be as big as her, so why bother?"
But ultimately, we as humans build on each other's works. It's the best way to progress. Why re-invent the wheel for everything each time? So much less productive.
Um, I don't know if you know this but artists being "ripped off" by the entertainment establishment is not exactly unheard of. In fact (though I don't know firsthand) I believe it's par for the course.
Then those 2.6 million people give physical copies to their friends and you're back to square one. That same theory has been trotted out every time someone has a new anti-piracy technology and wants people to believe that this time, it will work. Every single thing has failed..
Most people aren't very good at cryptography. But it only took a few people to write DeCSS and a few more to run it, then everyone had DVD rips. Same for BDs, same for video game copiers especially back when they were cartridges instead of DVDs. Same for everything else.
The same exact story has been repeated over and over. Why do you think it will be different this time? Do you think it will be more successful because the government is calling the shots now?