If you see a bat signal, or rather a laughing cat signal, hovering in the sky over Gotham City, San Francisco or New York this Thursday night, it won't just be a sign that the new Batman flick has opened. It will be a sign that the Internet Defense League has come to save the world – or at least the online part of it.

That's when the IDL, a grassroots group, plans to pick up where the successful crowdsourced campaigns against SOPA (Stop Online Piracy Act) and PIPA (Protect Intellectual Property Act) left off.

In those landmark protests, numerous websites and activists held rallies offline and mobilized online to take parts of the internet dark for a day in order to defeat self-serving bills backed by Hollywood companies and their lobbyists that sought to make core changes to internet infrastructure under the guise of fighting copyright infringement.

Now the Internet Defense League hopes to leverage that people power against future threats by enlisting website owners, activist groups and others to organize now in order to respond quickly when the next attack on internet freedom arises.

"This is something that's been percolating around with a lot of people post-SOPA. What could we do to get more organized if another threat were on the horizon?" said Rainey Reitman, activism director for the Electronic Frontier Foundation and a member of the IDL's steering committee.

The idea for the League originated with Holmes Wilson, a co-founder of the activist group Fight for the Future, and colleague Tiffiniy Cheng. They approached the EFF to get support, and since then Mozilla has joined up, as has Public Knowledge and Reddit. The group also received early help from volunteer developers, including employees of Cloudflare.

"When we organized the American Censorship Day in November, we were able to reach many more people than if we got all of the tech non-governmental organizations involved," says Wilson. "[That's] what allowed us to defeat a bill like SOPA that had such tremendous lobbying effort behind it. Now the Internet Defense League is our tiny organization's attempt to bootstrap something bigger, something that should've started long ago.... When the interests of users, small startups, and established companies align as they did against SOPA, there is no excuse for us to lose a policy battle."

Reddit co-founder Alexis Ohanian, who is also on the steering committee, said the fight for internet freedom is something that everyone can get behind, whether they're liberal activists or Tea Party patriots.

"This is such a non-partisan issue," he says. "Regardless of your political stripe, you have to concede that the open internet is a good thing for the country. The nice thing about SOPA and PIPA was that Moveon.org was there right next to the Tea Party. It was pretty much Everyone vs. the entertainment industry."

Whether someone has control over a single YouTube page or a monster community site like Reddit, they'll be able to participate in whatever way suits them best, he says.

"At a moment of notice, this kind of digital bat signal will go up in the air and you'll get notified and have the opportunity to take action however you see fit on your site," Ohanian says. "It could be a slew of buttons that give links to whatever we're doing, a call to action to sign a petition, or a couple of lines of code that you put on your site that allows someone to call their senator. It will be up to the web owner to decide.... We're trying to encourage as much from the bottom up, because that's how the internet works."

The group will formally launch midnight Thursday to coincide with the opening of the latest Batman movie The Dark Knight Rises, piggybacking on the very Hollywood machine that spawned the League.

The plan is to host parties in San Francisco, New York, Washington, D.C., London and Ulaar-bataar, Mongolia, and raise money to fund "cat signal" spotlights to shine over party cities that night.

The group's name and excessive Batman metaphors were born out of the many "heroic ways" in which people stepped up to kill the copyright bills.

"The idea is that everyday people are turning into heroes for the internet," said Reitman, and are beginning to see that they "are responsible for safeguarding our online Gotham."

After SOPA was defeated, Wilson says, the idea for having a "bat signal for the internet" was kicked around a lot in forums.

"While the Internet Defense League idea was brewing, people started calling it 'a bat signal for the internet,' and we ran with it," he says. "Except that if the internet has a mascot, it's definitely a cat, not a bat.‬"

Hence the lolcat spotlights.

As the group gets organized, it's still unclear who exactly will play the coveted role of Commissioner Gordon and get to flash the cat signal to call in the superheroes when the time is right. Also unclear are the exact parameters for determining when an outrage against open-net principles deserves superhero action as opposed to simply an impassioned Tweet campaign and biting blog posts.

Reitman notes that given the fact that "we are constantly bombarded by internet threats," one of the major challenges for the group is going to be "to not abuse the bat signal."

Another one will be to not abuse the Batman references.