Several prominent websites held online protests on Wednesday over anti-piracy legislation (Stop Online Piracy Act and Protect Intellectual Property Act) that is being considered by Congress.

Wikipedia made the most noise, holding a complete blackout for 24 hours. Others like Craigslist and Google posted messages linking users to information about the two bills. Google blacked out the logo on its home page, directing people to a page where they could add their name to an online petition. And Craigslist changed its local home pages to a black screen directing users to an anti-legislation page.

SOPA and PIPA would change how copyright holders seek to remove infringing content from the Internet. The legislation aims to shut down sites that share pirated movies and other content.

The companies were joined by many in Hollywood, who are concerned that SOPA and PIPA could be used to target legitimate websites.

Three Republican co-authors said they have softened their stances on the bills, which are still being considered by Congress.