After being tipped of this article, I decided to share it here: http://www.digitalspy.co.uk/gaming/news/a362679/minecraft-studio-apologises-over-racist-translation.html
This could happen with our project too, so please be alert and tell us if you find any swearing, racism, sexual content or offensive harassments in the language you play the game in.
Stuff like this is not tolerated at all.
Until now I have just checked the uploaded language files for common coding errors, but from now I will do some searches with Google translate for unwanted words and phrases before committing such files.
I encourage all other translation committers to do the same.
Since we cannot proof-read 100 % of the text (can't know every language), I strongly recommend that you report anything you might find offensive in your own language.
I don't think this is a big issue with our project, but better safe than sorry.