You're right. Facebook (and Wikipedia) have to deal with this same problem. This is why tr8n provides a mechanism for translators to vote on the quality of translations. And there are also admin tools for suspending translators, adding a vote threshold for translations to go live and a block list as well. Also, users can report a translation, which immediately puts the translator on a watch list.

Also, don't forget, in a crowd-source environment, there will almost always be more language protectors than vandals.

Any thought to integrate with Mechanical Turk? Some sites with lower visitor counts may not have the user base for this to work. I've written a Rails gem that makes Mechanical Turk integrations fairly trivial for Rails apps. (https://github.com/aantix/turkee) Hopefully this could help.

Good, you've thought of smartarse response like mine. But I personally would still be wary.