<rant>
I really dislike if software ignores my setting of $LC_MESSAGES=C and shows me its UI in German, just because I set $LANG=de_DE. I hate that. I don't want no UI strings in German, the translations are mediocre. I want everything else in German (paper sizes, ...), but no strings please. That's why I configured my locale settings this way. I don't want those settings ignored.
Please, developers, read through locale(7) and related man pages before you hack up i18n support. Thank you.
The offenders that pissed me off right now are Firefox and Fedora's man.
</rant>