Internet-based encyclopedia Wikipedia made its digital voice heard when it blacked itself out for 24 hours to protest two U.S. bills intended to battle online piracy.

Wikipedia posted a "thank you" note online after its blackout ended at 12 a.m. ET Thursday, stating more than 162 million people saw its message asking "if you could imagine a world without free knowledge.

"You said no."

The action also highlighted the power of social media.

One tweet making the viral rounds during the blackout was, "Under SOPA, you could get 5 years for uploading a Michael Jackson song, one year more than the doctor who killed him."

Others put up "Stop SOPA" banners on their Twitter pages.

With Hollywood producers and unions flexing their muscles with American legislators, those in favour of a "free and accessible" Internet are crying foul over SOPA and PIPA.

SOPA, or the Stop Online Piracy Act, and PIPA, the Protect IP Act, are seemingly innocent in their intent: stop foreign copyright theft so artists, drugmakers and their related industries can make money.

But Internet stalwarts like Wikipedia and its supporters like Google argue the laws would undermine innovation and free speech, perhaps even changing the architecture of the Web and how search engines work.

Why are the laws needed?

Creative America, a collection of Hollywood artists and industry types, says content theft costs U.S. workers $5.5 billion a year.

How do SOPA and PIPA work?

There are already laws that protect copyrights on domestic websites that offer access to pirated goods, but there's nothing to control offshore operations.

SOPA and PIPA would allow the U.S. Justice Department and copyright holders to seek court orders against foreign websites accused of piracy.

Since there's not much the U.S. can do to take down such foreign sites, the bills would instead prevent online advertising networks and payment firms such as credit card companies and PayPal from doing business with them.

Search engines could be prevented from linking to these sites. Copyright holders and Internet service providers would be able to block access to the pirate sites as well.

Why are Wikipedia and Google opposed?

By altering search engines, the very nature of the Internet could be changed by interrupting the automatic flow of web crawling, critics argue, and hinder free speech at the same time by controlling what content people could access.

Deliberate search failures could also open the door to hackers who could redirect users to websites that contain malicious software, creating new cyber security risks.

The latter provisions of the bills appear now to be doomed, with even the Motion Picture Association of America declaring DNS filtering was "off the table" this year.

Does that mean Wikipedia's protest was fruitless?

Critics say ‘no' because the bills still contain provisions that affect free speech, due process and online innovation.

The bills remain up for debate and likely many amendments will be added before they appear before U.S. President Obama for ratification, although a few key supporters of the bills in Congress appear to be backing down.

Wikipedia added in its ‘thank you' message: "The internet has enabled creativity, knowledge, and innovation to shine, and as Wikipedia went dark, you've directed your energy to protecting it.

"We're turning the lights back on. Help us keep them shining brightly."