For how long has as Facebook been hijacking the back-button?
When I followed this link https://www.facebook.com/nick.moore.7140/posts/3600186133211 from another HN post, I noticed that the back-button was not active, as if I typed the URL directly, or opened the page in another tab. This was on Firefox. Is this new. I don't visit FB that often, so I may just not have noticed it. Is everyone all right with this? I'm not. Do you have the Facebook Container extension activated in Firefox? It automatically opens all fb links in a new session as if you opened a new tab, so the back button won't work. You might be able to get back to the previous page by re-opening it with ctrl+shift+t. Being able to hijack the back button like that would be either a browser bug, or feature like 0xBE5A describes.