Reddit, Pornhub, Tumblr, and other companies are supporting an upcoming net neutrality vote with a new publicity campaign. The Red Alert for Net Neutrality project is organized by activist groups Demand Progress, Free Press Action Fund, and Fight for the Future, which have run similar awareness campaigns in the past. It’s drawing attention to an upcoming vote in Congress, where Sen. Ed Markey (D-MA) and others are trying to restore net neutrality rules that were repealed last year.

This protest seems lower-profile than last year’s net neutrality day of action, supported by giants like Google, Facebook, and Amazon, but it still has several big sites and services on board. Participants include Tinder, the Wikimedia Foundation, Vimeo, Imgur, Etsy, Mozilla, GitHub, and more organizations listed here. There’s also a widget that anyone can put on their site, urging people to contact their congresspeople.

Why start today? Because today, a group of senators (led by Markey) are petitioning for a vote on 2017’s net neutrality repeal. They’re using the Congressional Review Act, a legislative tool that lets Congress reverse federal regulations with a simple majority vote. Under the CRA, any 30 senators can force a vote to be scheduled, rather than waiting for a committee decision. The Red Alert campaign is supposed to start with a high-visibility push today, then simmer until right before the vote — whenever that turns out to be.

Democrats unanimously support this resolution, so it could pass the Senate if two Republicans flip to vote with them; right now, one — Sen. Susan Collins (R-ME) — has pledged support. The resolution has a lower chance of succeeding in the House of Representatives, and President Trump could ultimately veto it, but it’s still considered one of the best chances to preserve net neutrality right now. Markey is running a Q&A session on Reddit at 2:30PM ET today, and websites should be launching their campaigns throughout the day.