In Planet of the Dead, the Doctor says to Christina that he can speak all languages.
The TARDIS doesn't translate, it uses it's telepathic field to slave the Doctors polyglottery into the immediate area... Think about how many thousands, maybe millions of conversations are being translated inside the TARDIS' proximity?
Now ask yourself if the TARDIS is keeping real time logs of any of these conversations and monitoring content and context that it shouldn't be able to FIND the badies before they strike in line with how the Machine on Person of Interest works.
We heard a Dalek speaking German once when Martha tred to blow up the world.