Withholding participation pending review.
I haven't read the text from SOPA or PIPA yet.
I've got friends and family who make or have made their livings from selling their intellectual property. They make something up, publish it, and other people pay for it, and they eat. "Piracy" undermines that. Someone who wants their product, and should by rights pay for it, gets it without paying.
Think of your favorite musician, writer, or programmer, and ask yourself what their incentive is to publish their work, if no one pays them for that work. This interferes with the free market.
A problem, of course, is that the Internet is not a national market; it is a global one. We can't control the world just because we say so.
In general, I'm against extra legislation. And of course the test to see if Sky-Is-Falling legislation is really needed is to stop for a day or two and see if, in fact, the Sky really is Falling.
I have some reading to do before I jump on any bandwagons, though.
And so do y'all.