I just got bitten by this. I was visiting a news site and opened ~30 tabs to things I wanted to read. And then those tabs just showed me an error message. Frustrating :(
Edit: Might be worth noting that logging out of FB "fixed" this for me. (But I had to go back and re-open all those tabs.)
works fine for me, perhaps because I have never used Facebook to log into it.
AFTER EDIT: Replying to the kind reply to this comment, I am ALWAYS logged in to Facebook (with AdBlock Plus and Social Fixer and Ghostery activated, using Chrome), and I was surfing all over the Web completely normally while sites were reported to be redirecting. So maybe something different about my set-up protected me from the problems many other users observed today.
With Ghostery running, it should not even load anything from a Facebook domain. The (buggy) code to redirect people to facebook.com would no doubt be served fromFacebook themselves. Stopping that code from being served to your browser means they can't redirect.
I absolutely love Ghostery and other related tools.
It's not whether you've ever used Facebook to log into The Economist's site, but whether you were logged into Facebook at all. If you were, you were redirected.
EDIT: By the timestamp on your comment, the issue appears to have been fixed, anyway.
