CNET has a great analysis of SOPA ("Stop Online Privacy Act"), also known as the E-PARASITE Act ("Enforcing and Protecting American Rights Against Sites Intent on Theft and Exploitation Act."): 

House leaders assured Silicon Valley they would correct serious defects in the Senate bill. Unfortunately, SOPA does just the opposite. It creates vague, sweeping new standards for secondary liability, drafted to ensure maximum litigation..

The House bill, for example, dubbed the "E-PARASITE Act," proposes alternative versions of several provisions from Protect IP, including new authority for the attorney general to cut off access and funding for "parasite" foreign Web sites. (SOPA requires the U.S. copyright czar to determine the extent to which these foreign infringers are actually harming U.S. interests, data collection that logically should precede such sweeping new powers.)

Once the Justice Department determines a site "or a portion thereof" is "committing or facilitating" certain copyright and trademark violations, it can apply for court orders that would force ISPs and others who maintain DNS lookup tables to block access to the site.

Search engines (a term broadly defined that includes any website with a "search" field), along with payment processors and advertising networks, can also be forced to cut ties with the parasites. Operators of innocent sites have limited ability to challenge the Justice Department's decision before or after action is taken.

SOPA also includes its own version of another Senate bill, which would make it a felony to stream copyrighted works. The House version allows prosecution of anyone who "willfully" includes protected content without permission, including, for example, YouTube videos where copyrighted music is covered or even played in the background.

While supporters deny that such minimal infractions would meet the bill's definition of "willfully," the actual text suggests otherwise. Prosecutors need only demonstrate that the use had a total "retail value" of more than $1,000. To avoid a felony conviction, a defendant would have to prove they reasonably believed their conduct was lawful, as for example someone in a "bona fide commercial dispute" over the scope of a license to use the content

The House bill also makes significant changes to provisions in the Senate bill that afford new enforcement tools to private holders of copyrights and trademarks. This "market-based system," as SOPA calls it, greatly extends existing provisions of the 1998 Digital Millennium Copyright Act, under which copyright holders can easily issue takedown notices for unlicensed use of protected content.

SOPA's "market based" provisions are not limited to foreign Web sites. Indeed, they apply to any site or "portion of" a site that is "dedicated to theft of U.S. property," a new category broadly defined by the bill. Under the new law, rightsholders could force payment and advertising networks to cut ties to such sites simply by sending a letter to their authorized agents (who must register with the U.S. copyright office). Site owners can object, in which case the private parties may sue to enforce their claims, similar to the new powers afforded the Department of Justice.

Unlike the DMCA, SOPA provides little penalty for wrongly targeting websites turn out not to be "dedicated to theft of U.S. property." Ad networks and payment processors are immune from liability if they fail to respond to a site's counterclaim, and damages to the site operator are only available if a claim "knowingly materially misrepresents" that the site satisfies the new definition.

These extensions are both extreme and unnecessary. For U.S.-based sites, the DMCA has proven highly effective, working in many cases automatically based on "reference files" provided by rightsholders. Though obviously not perfect, economists and legal scholars believe the DMCA has proven to be a cost-effective solution that protects content without squelching innovation...

Here is CNET's previous coverage of theProtect IP Act, the Senate version of the act. For more information check out EFF's analysis (Disastrous IP Legislation Is Back – And It’s Worse than Ever) and coverage on Tech Dirt. Here is a Whitehouse.gov petition to stop the act.