SOPA is being aggressively pushed by Hollywood movie studios, major record labels and luxury goods providers as an effort to crackdown on internet piracy of their products. But the tools envisioned are so extreme that tech experts warn the legislation threatens the very functionality of the Internet. The ACLU and other free-speech groups emphasize that by authorizing the federal government and corporations to shut down entire websites without a trial for posting just a single piece of copyright-infringing content, the bill would sharply curb the exercise of free speech online.