The theme for the last days is the question marks instead of Unicode characters in various software products. In this case Facebook.
Facebook? Have you read this article written by Andrei Alexandrescu?
funny video (in Romanian) page you can see the caption as: „Primul șlagăr care te învață să scrii corect înjurăturile.”. No question marks there!
I'm sure there is an explanation why that happened... but it shouldn't have happened. Nobody said that Unicode is easy!
P.S. It seems Google+ does the same thing: