During the Web protest against antipiracy legislation, Firefox blacked out its start page and redirected users to Mozilla's anti-SOPA and PIPA action page. It also posted 9 million messages about the two pending bills on Facebook, Twitter, and in its Firefox + You newsletter.

As a result, more than 40 million people were reached, CNET reports citing Mozilla News.

"All these steps were aimed at informing and mobilizing millions of people on the poorly drafted anti-piracy legislation - SOPA and PIPA-pending in Congress," Alex Fowler wrote in The Mozilla Blog.

According to Fowler, around 30 million people in the U.S. use Firefox's default start page, which reached the lion's share of users; and the social media messages Mozilla sent out were retweeted, shared, and liked by more than 20,000 people.

As a result of Mozilla's campaign, 360,000 e-mails were sent to senators and members of Congress, 1.8 million people went to mozilla.org/sopa to learn more about the antipiracy laws, and 600,000 went on to visit the Strike Against Censorship page that is hosted by the Electronic Frontier Foundation, Fowler said.

Other major Web sites also launched informational and take-action campaigns. Google redirected users to sign a petition being sent to Congress and the Senate that more than 7 million people signed. Wikipedia completely blacked out its English language site and provided information for people to protest SOPA and PIPA.

It's likely that this isn't the last that U.S. legislators will hear from these protesters. "The debate is far from over," Fowler wrote. "Keep the pressure on and make sure your elected officials understand the nuance of the issue and the importance of protecting the open Web."