The Battle For the Net website mentions a vast range of online companies who apparently stood in solidarity to take action on this day.
* Github: a blog post displayed on your feed.
* Etsy: Nothing.
* Kickstarter: Nothing.
* Netflix: Nothing.
* Twitter: Nothing.
* Vimeo: A featured video on the landing page.
* Reddit: A tiny blurred logo.
* Hacker News: A grey bar!
* Mozilla: Nothing.
* OkCupid: Nothing.
What a great display!