Regardless of what you think about ethics of piracy, it is there because the model of selling creative work is not only unreasonable - it's fucking insane.
Let's see how this goes with physical goods. The manufacturer buys raw material and pays his workers to produce a batch of items for him. Then he sells it for more money. The price of one item includes mostly the price of the material and the worker's payment. It's also a bit inflated, because the company needs to make money, after all. This surplus also covers for the marketing and distribution costs, which are pretty significant. Last but not least, it also should cover the cost of the creative work done before the manufacturing process - design, for example.
When this surplus is pretty small, all goes well. The potential buyer can try to make the same product at home, but it's unlikely it would be profitable for him. After all, mass production is more cost-effective, that's why most of our goods are produced in factories, instead in artisans' workshops. He can steal the product, but it can be dangerous to him - being caught, even if not so likely, would cost him much more than the stolen goods. He can do this if he's desperate enough - for example, he is starving and needs some food - but, in most cases, he will just buy the product.
The problem appears when this surplus is not small. For example, designing a medicine is quite difficult, but manufacturing it is usually a simple process which doesn't require expensive ingredients. Patents are supposed to level that difference - the researching company can artificially inflate their price for some time to cover the cost of development. It's far from being a great solution, but at least it can work, as distribution of counterfeit goods is quite risky and expensive in itself.
Then we have digital goods, where manufacturing and distribution carries almost no cost at all. It's a process so simple that potential buyers can do it by themselves. To make a profit, the designer only needs to cover a single expenditure (designing the digital good) and the cost of selling individual copies. And, of course, hype. Even copyright isn't enough here - laws add some risk to otherwise profitable activity and copying copyrighted material isn't very risky. Yet.
There is also a thing that copyright holders often do not mention: they only need to produce (or buy) a digital good once and they get to sell it as many times as he can. He can also profit from any work that is in some way derivative from the one he holds his right to. Mind it, their employees are still paid like ordinary workers, though - they get their salary (or one-time payment) and usually don't see even a penny from those profits. Anytime you think about the losses piracy bring, think about those profits. It's something that most ordinary manufacturers can see only in their wildest dreams.
So, of course, all these restrictive laws like SOPA or PIPA do have a point. They are the only chance this flawed business model has. They need to be even more draconian, as piracy becomes easier and cheaper each day. Of course, it means that we would pay money (in form of taxes) to the government to better prevent us from getting creative works cheaper. I see no reason for the ordinary citizen to support it.
The one thing we can hope for is that the current situation is somewhere near the equilibrium - the piracy won't be stamped out, but enough user will still buy digital goods to support this business model. It seemed possible, after all, several years ago. But the science marched on, new ways of piracy slowly become possible (see 3D printers and "physibles" - not miuch right now, but you can see where it leads), and our governments has turned out to be much less controllable by an ordinary voter than we thought. It's now quite obvious they won't support the balance between the consumers and copyright holders. So we may expect even more stupid and restrictive laws and acts, until the whole model becomes so obsolete and ineffective it collapses under its own weight. It won't kill the entertainment industry - the people will still need it, after all. But it will certainly be painful, especially for the biggest players (and their employees, too!). The best thing that could be done is finding alternative ways to pay the author.
The one thing that I don't think should be done is defending the current way of selling digital goods. Even if you don't support SOPA or similar laws, you are using the same arguments that are used to push them. Moreover, it isn't even advantageous to you. If you do some kind of creative work, you most probably do it for someone who pays you a small fraction of the money he gets. He will profit from your work long after you get laid off or decide to work somewhere else. You still will be a consumer of creative works, why defend his rights instead of yours?