You're probably used to pop-ups on websites begging you to sign-up for an email newsletter, enter a contest, or watch an ad. But tomorrow the web will be plastered in a different sort of pop-up as some the tech's biggest companies fight to maintain a free and open internet.

Last May, the Federal Communications Commission began the process of dismantling the net neutrality rules it adopted in early 2015. Without these rules, internet service providers could be free to block you from viewing particular sites, throttle the speeds of video streaming services, or charge you extra to view particular content. The end of net neutrality could make it much harder for new companies to get a toe-hold in markets such as streaming media or video calling, or even stifle free speech online.

Tomorrow, sites across the web will place alerts on their pages encouraging people to send letters to the FCC asking the agency not to jettison net neutrality. Hundreds of companies and organizations plan to participate in this so-called "Day of Action," from giants such as Amazon, Google, Facebook, and Netflix to Reddit, Etsy, PornHub, Spotify, and even some smaller internet service providers like Ting and Sonic.

The plan is reminiscent of a similar campaign in January 2012, when countless websites, including Google, Wikipedia, and WIRED, blacked out parts of their pages to raise awareness about a pair of draconian intellectual property reform bills known as SOPA and PIPA that Congress was debating at the time. The campaign worked. Voters flooded their representatives with emails, phone calls, and letters, and the two bills died an early death.

It was a crucial moment in the history of internet policy and proved that activists and web companies could mobilize the public to push back against harmful legislation, and now the organizers behind the Day of Action are hoping to repeat that success. But not every company is equally committed to the cause of net neutrality. Here's where seven internet giants stand on the issue, and what a world with fast and slow lanes might mean for them.

Amazon

Jeff Bezos's everything store was the first web giant to lend its name to this week's Day of Action when the campaign was announced last month. And though it hasn't always been the most vocal supporter of net neutrality, it is part of the Internet Association, which has quietly lobbied in favor of keeping the current rules intact. It was also one of the 100 groups that signed on to an open letter to the FCC in 2014 calling for strong net neutrality rules.

In some ways, Amazon is an unlikely champion of net neutrality. Its e-commerce business is by far the biggest player in online shopping, and slightly slower download speeds aren't likely to change that. But Amazon's video streaming service is another story. It's garnered some big awards, but according to comScore, it still trails Netflix in viewership. The end of net neutrality might not be a death blow to Amazon's streaming media ambitions, but the retail giant clearly doesn't want to deal with getting squeezed by the broadband industry at the same time it tries to claw marketshare away from Netflix.

And then there's Amazon's cloud computing service, which is the main reason the company has lately been in the black so often after years of running at a loss. What's more, some of its services, such as CloudFront, compete directly with services sold by telcos. That means Amazon could end up having to pay its competitors to keep its services speedy, giving the telcos the chance to undercut Amazon if the company passes the new fees on to consumers. The end of net neutrality might not be enough to kill Amazon's cloud, but it could whittle down its margins.

Apple

Apple has long been absent from the net neutrality debate. The company was not one of the 100 companies that signed the open letter supporting net neutrality in 2014, it's not a member of the Internet Association, and it hasn't announced any plans to participate in the day of action this week.