SOPA and PIPA enable the government and private individuals and (of course!) corporations to target and block content and websites they don't like, without ever showing in a court of law or proving to anyone but themselves that the content or the website infringes copyright.
This is not about how you feel about people stealing copyrighted works; it's not about whether we believe "data should be free." It's not about that, any more than the power to detain and imprison an American citizen and supposed "terror suspect" without probable cause or recourse to habeas corpus is about how you feel about a plane smacking into the World Trade Center.
Once you excuse the government from having to prove wrongdoing in a court of law, you can forget about who the law is supposed to target or what it is supposed to do, because there is no longer any mechanism for the target or anyone to use the courts to confine the law to its original targets. The Founders understood this. Do we?