For example... go to google translate.
Enter "Let's drink tea.", select English to Korean and translate.
Paste the result ("차를 마시자.") in to the box and translate back to English.
Surprisingly, the outcome is "Drink the car." What? Right...
It might be a good idea not to be organising any tea parties in Korean using translation tools to communicate for the time being...
Japanese isn't so accurate either: translating "I like to drink tea" to Japanese and back to English yields "I like the fact that brown is drunk". Firstly, that stuff should be solid or you should be seeing a doctor, and anyway, I don't want anybody drinking my brown. That goes straight in the jar under my bed.
Update 4th February 2011
- Now translating "Let's drink tea." to Korean and back results in "Janhaja tea". Eh.
- The Japanese round-trip for "I like to drink tea" is now accurate.
It's a pity I didn't save some more bad examples of which I compiled quite a few, to see how the state of the art (assuming Google Translate is reasonably representative of this) has advanced in the last four years.