Both measures would require Internet operators to police activity online, and would mandate Internet giants like Google and AOL (the parent company of The Huffington Post and an opponent of the bills) and credit card companies to take down sites that have content deemed to be in violation of copyright rules.
The battle has pitted huge content generators like Disney and the motion picture industry against their online competitors, with each side reportedly spending some $90 million on lobbying efforts.
Supporters say the measures will help curb theft and preserve the integrity of the Internet. Opponents charge that the measures amount to censorship that will stifle innovation and impose higher costs on consumers.