It's a problem that affects anyone who wants something written in a foreign language but doesn't speak the language himself or herself: how do you know what the translator has written is correct? You can get someone else to double-check it of course, if you have the time and budget, but most people just take the first translation and hope for the best.
But, of course, people make mistakes all the time. Or are just untrustworthy.
This sign in Swansea, for example, is a famous illustration of the problem:
Someone who didn't speak Welsh needed a Welsh translation so emailed the English wording to the council translation department. They got an email back, assumed it was the translation and used that. Unfortunately, what the Welsh wording actually says is: "I am not in the office at the moment. Send any work to be translated."
The latest season of Homeland suffers from a similar but differently motivated problem. The series has earned itself a reputation in some quarters as being racist to Arabs. Unfortunately, despite being set in Berlin for the latest season, one scene needed to show a Syrian refugee camp. And the producers thought that meant there would be pro-Assad graffiti on the walls of the camp, so they commissioned some Arabic-speaking artists to write some suitable graffiti for them.
Unfortunately, the artists in question weren't impressed by Homeland so took a few liberties.
For those of you who don't read Arabic, that one says: "Homeland is racist."
"Homeland is not a series", "The situation is not to be trusted", "This show does not represent the views of the artists".
One of the artists explained to The Guardian: "We think the show perpetuates dangerous stereotypes by diminishing an entire region into a farce through the gross misrepresentations that feed into a narrative of political propaganda.
“It is clear they don’t know the region they are attempting to represent. And yet, we suffer the consequences of such shallow and misguided representation.”
So remember: always get your translations double-checked. Translators get paid little enough as it is, so if you double the amount of work available for them, maybe they'll all be a bit better off. As will your TV shows.