With no comment from me, I'll let Peter Lewis on "Our Mechanical Brain" tell you about how Rosetta Stone tried to create a festive advertisement for their language-learning software and managed to get a three-word sentence wrong in each of three different languages, and two out of the three wrong even on the second try. Read Peter's account here. And remember, when it's language, people never check. They never call a linguist. They just make stuff up.
Update: Rosetta Stone got in touch with Language Log and asked for space to respond. We're happy to provide that, of course. Here is what they said:
In a word, we’re ashamed. We tried to capture the spirit and meter of a popular Christmas tune and, regrettably, our enthusiasm for spreading marketing cheer outpaced our respect for linguistic accuracy. We green-lighted an ad before its time. The fact is, we have a stringent pedagogical approval process at Rosetta Stone, and we missed an important check-point here. There’s no excuse. The ads have been recalled. We assure you that from here on out, no one at Rosetta Stone–including marketing–will be taking shortcuts. We’re sure that this post will invite more thoughtful (even heated) criticism, and we hope you’ll understand if we don’t engage further in the dialogue for the moment—we have important work to do on the home-front. Thank you for keeping us in check and have a great holiday. (Hey, maybe we’ll try ‘Silent nuit, holy Nacht’….)