The company responsible seems to have responded in the comments:

"It was definitely a mistake on our part. The problem was not the encoding on our data feed, but the HTML document was sent with ISO-8859-1. The second we inserted the twitter text into the DOM, the browsers interpreted the UTF-8 string as ISO-8859-1. Our visualizations are hosted on other platforms, and in this case the server was not configured to send UTF-8 with text/html even though the HTML file was encoded as such. It was the only issue (albeit a pretty obvious one) during an otherwise flawless event. I apologize to President Obama, Speaker Boehner, and Jack Dorsey for the mistake. If the readers of the blog think it was stupid, imagine how we felt. dev environment != production environment. If we would have just included a <meta charset="utf-8"> in the HTML head, then this would not have occurred.

The big take away is don’t make assumptions about other platforms (especially when it comes to encoding), and always include charset meta tag." [emphasis mine]

Was emailing involved? We've been getting so much support questions regarding encodings of HTML emails (we're a programmatic email service: http://mailgun.net) that we actually decided to become the first MTA to enforce utf-8 transcoding on the entire traffic: randomness in -> clean utf8 out and everyone is suddenly quiet&happy.

Something like this could be done as nginx/apache module: which detects encodings of the data and transcodes the HTML output into utf8 - could be useful for some cases.

Including <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> is like the first thing you do when starting front-end development.

Every time you don't validate...God kills a kitten. Please, think of the kittens.

This has been a Public Service Announcement. Please code responsibly: http://validator.w3.org/

Just for the record, the correct spelling is now:

  <meta charset="utf-8">

How do you (or the OP) know the implementation details of the consumption path for display? The author assumes it was the direct JSON feed from Twitter. That's overly simplistic and betrays his inability to understand how these sort of things are put together. This is a public, real-time event; more likely than not tweets were filtered through one or two other components to separate the interesting material from the noise. You have no idea what those intermediary components were, who set them up, and if they were all decoding/reencoding correctly. Perhaps they were going through other Twitter users' clients, which could have contributed to the bug.

Edit: yes, there were definitely people curating the questions, so it could not have been as simple as pulling one JSON feed. http://www.theatlantic.com/politics/archive/2011/07/how-obam... https://twitter.com/#!/townhall/july-6-curators

> You have no idea what those intermediary components were, who set them up, and if they were all decoding/reencoding correctly.

...That's kind of the point. There was someone being sloppy there.

Yup, it can also be much more serious than some garbled text. Google "canonicalization vulnerabilities" and see stuff like this: http://www.amarjit.info/2009/09/canonicalization-vulnerabili...