What modern software stack uses Extended ASCII as its default encoding? The last time I dealt with this problem, it was in 2005 or 2006 and I was working with PHP.
The article's comments says the problem was that the (implicit) character encoding of the HTML page:
"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."
